Isoquinoline derivatives and use thereof

ABSTRACT

The Invention provides compounds of Formula (I) and pharmaceutically acceptable salts, solvates, hydrates, N-oxides, or diastereomers thereof: wherein W 1 , W 2 , W 3 , J 1 , J 2 , A, R 1 , R 2 , R 3 , R 4 , R 5 , a, and b are defined as set forth in the specification. The Invention also provides uses of the compounds of any one of Formulae (I)-(VIII) and the pharmaceutically acceptable salts, solvates, hydrates, N-oxides, or diastereomers thereof. Compounds of the Invention are useful for treating a disorder responsive to blockade of one or more sodium channels. In certain embodiments, Compounds of the Invention are useful for treating pain.

FIELD OF THE INVENTION

This invention is in the field of medicinal chemistry. The Inventionprovides novel isoquinoline derivatives. In certain embodiments, theisoquinoline derivatives are useful for treating a disorder responsiveto blockade of one or more sodium channels.

BACKGROUND OF THE INVENTION

Voltage-gated sodium channels (VGSCs) are found in all excitable cells.In neuronal cells of the central nervous system (CNS) and peripheralnervous system (PNS) sodium channels are primarily responsible forgenerating the rapid upstroke of the action potential. In this mannersodium channels are essential to the initiation and propagation ofelectrical signals in the nervous system. Proper function of sodiumchannels is therefore necessary for normal function of the neuron.Consequently, aberrant sodium channel function is thought to underlie avariety of medical disorders (See Hubner et al., Hum. Mol. Genet.11:2435-2445 (2002) for a general review of inherited ion channeldisorders) including epilepsy (Yogeeswari et al, Curr. Drug Target5:589-602 (2004)), arrhythmia (Noble, Proc. Natl. Acad. Sci. USA99:5755-5756 (2002)), myotonia (Cannon. Kidney Int. 57:772-779 (2000)),and pain (Wood et al., J. Neurobiol., 61:55-71 (2004)).

VGSCs are composed of one α-subunit, which forms the core of the channeland is responsible for voltage-dependent gating and ion permeation, andseveral auxiliary β-subunits (see, e.g., Chahine et al., CNS &Neurological Disorders-Drug Targets 7:144-158 (2008) and Kyle and Ilyin,J. Med. Chen. 50:2583-2588 (2007)). α-Subunits are large proteinscomposed of four homologous domains. Each domain contains six α-helicaltransmembrane spanning segments. There are currently nine known membersof the family of voltage-gated sodium channel α-subunits. Names for thisfamily include SCNx, SCNAx. and Na_(v)x.x (sec TABLE 1, below). The VGSCfamily has been phylogenetically divided into two subfamilies Na_(v)1.x(all but SCN6A) and Na_(v)2.x (SCN6A). The Na_(v)1.x subfamily can befunctionally subdivided into two groups, those which are sensitive toblocking by tetrodotoxin (TX-sensitive or TTX-s) and those which areresistant to blocking by tetrodotoxin (TTX-resistant or TTX-r). Thereare three members of the subgroup of TTX-resistant sodium channels. TheSCN5A gene product (Na_(v)1.5. Hl) is almost exclusively expressed incardiac tissue and has been shown to underlie a variety of cardiacarrhythmias and other conduction disorders (Liu et al., Am. J.Pharmacogenomics 3:173-179 (2003)). Consequently, blockers of Na_(v)1.5have found clinical utility in treatment of such disorders (Srivatsa etal., Curr. Cardiol. Rep. 4:401-410 (2002)). The remaining TTX-resistantsodium channels, Na_(v)1.8 (SCNI0A, PN3, SNS) and Na_(v)1.9 (SCN11A,NaN, SNS2) are expressed in the peripheral nervous system and showpreferential expression in primary nociceptive neurons. Human geneticvariants of these channels have not been associated with any inheritedclinical disorder. However, aberrant expression of Na_(v)1.8 has beenfound in the CNS of human multiple sclerosis (MS) patients and also in arodent model of MS (Black et al., Proc. Natl. Acad. Sci. USA97:11598-115602 (2000)). Evidence for involvement in nociception is bothassociative (preferential expression in nociceptive neurons) and direct(genetic knockout). Na_(v)1.8-null mice exhibited typical nociceptivebehavior in response to acute noxious stimulation but had significantdeficits in referred pain and hyperalgesia (Laird et al., J. Neurosci.22:8352-8356 (2002)).

TABLE 1 Voltage-gated sodium channel gene family Gene Tissue TTX IC₅₀Disease Type Symbol Distribution (nM) Association Indications Na_(v)1.1SCN1A CNS/PNS 10 Epilepsy Pain, seizures, neurodegeneration Na_(v)1.2SCN2A CNS 10 Epilepsy Epilepsy, neurodegeneration Na_(v)1.3 SCN3A CNS 15— Pain Na_(v)1.4 SCN4A Skeletal muscle 25 Myotonia Myotonia Na_(v)1.5SCN5A Heart muscle 2,000 Arrhythmia Arrhythmia Na_(v)1.6 SCN8A CNS/PNS 6— Pain, movement disorders Na_(v)1.7 SCN9A PNS 25 Erythermalgia PainNa_(v)1.8 SCN10A PNS 50,000 — Pain Na_(v)1.9 SCN11A PNS 1,000 — Pain

The Na_(v)1.7 (PN1, SCN9A) VGSC is sensitive to blocking by tetrodotoxinand is preferentially expressed in peripheral sympathetic and sensoryneurons. The SCN9A gene has been cloned from a number of species,including human, rat, and rabbit and shows ˜90% amino acid identitybetween the human and rat genes (Toledo-Aral et al., Proc. Natl. Acad.Sci. USA 94:1527-1532 (1997)).

An increasing body of evidence suggests that Na_(v)1.7 plays a key rolein various pain states, including acute, inflammatory and/or neuropathicpain. Deletion of the SCN9A gene in nociceptive neurons of mice led toan increase in mechanical and thermal pain thresholds and reduction orabolition of inflammatory pain responses (Nassar et al., Proc. Natl.Acad. Sci. USA 101:12706-12711 (2004)).

Sodium channel-blocking agents have been reported to be effective in thetreatment of various disease states, and have found particular use aslocal anesthetics, e.g., lidocaine and bupivacaine, and in the treatmentof cardiac arrhythmias, e.g., propafenone and amiodarone, and epilepsy,e.g., lamotrigine, phenytoin and carbamazepine (see Clare et al., DrugDiscovery Today 5:506-510 (2000); Lai et al., Annu. Rev. Pharmacol.Toxicol. 44:371-397 (2004); Anger et al., J. Med. Chem. 44:115-137(2001), and Catterall, Trends Pharmacol. Sci. 8:57-65 (1987)). Each ofthese agents is believed to act by interfering with the rapid influx ofsodium ions.

Other sodium channel blockers such as BW619C89 and lifarizine have beenshown to be neuroprotective in animal models of global and focalischemia (Graham et al., J. Pharmacol. Exp. Ther. 269:854-859 (1994);Brown et al., British J. Pharmacol. 115:1425-1432 (1995)).

It has also been reported that sodium channel-blocking agents can beuseful in the treatment of pain, including acute, chronic, inflammatory,neuropathic, and other types of pain such as rectal, ocular, andsubmandibular pain typically associated with paroxysmal extreme paindisorder; see, for example, Kyle and Ilyin., J. Med. Chem. 50:2583-2588(2007); Wood et al., J. Neurobiol. 61:55-71 (2004); Baker et al., TRENDSin Pharmacological Sciences 22:27-31 (2001); and Lai et al., CurrentOpinion in Neurobiology 13:291-297 (2003): the treatment of neurologicaldisorders such as epilepsy, seizures, epilepsy with febrile seizures,epilepsy with benign familial neonatal infantile seizures, inheritedpain disorders, e.g., primary erthermalgia and paroxysmal extreme paindisorder, familial hemiplegic migraine, and movement disorder: and thetreatment of other psychiatric disorders such as autism, cerebellaratrophy, ataxia, and mental retardation; see, for example, Chahine etal., CNS & Neurological Disorders-Drug Targets 7:144-158 (2008) andMeisler and Kearney, J. Clin. Invest. 115:2010-2017 (2005). In additionto the above-mentioned clinical uses, carbamazepine, lidocaine andphenytoin are used to treat neuropathic pain, such as from trigeminalneuralgia, diabetic neuropathy and other forms of nerve damage (Taylorand Meldrum, Trends Pharmacol. Sci. 16:309-316 (1995)). Furthermore,based on a number of similarities between chronic pain and tinnitus,(Moller, Am. J. Otol. 18:577-585 (1997); Tonndorf, Hear. Res. 28:271-275(1987)) it has been proposed that tinnitus should be viewed as a form ofchronic pain sensation (Simpson, et al., Tip. 20:12-18 (1999)). Indeed,lidocaine and carbamazepine have been shown to be efficacious intreating tinnitus (Majumdar, B. et al., Clin. Otolaryngol. 8:175-180(1983); Donaldson, Laryngol. Otol. 95:947-951 (1981)).

Many patients with either acute or chronic pain disorders respond poorlyto current pain therapies, and the development of resistance orinsensitivity to opiates is common. In addition, many of the currentlyavailable treatments have undesirable side effects.

In view of the limited efficacy and/or unacceptable side-effects of thecurrently available agents, there is a pressing need for more effectiveand safer analgesics that work by blocking sodium channels.

BRIEF SUMMARY OF THE INVENTION

In one aspect, the Invention provides isoquinoline derivatives asrepresented by Formulae I-VIII, provided infra., and pharmaceuticallyacceptable salts, solvates, hydrates, N-oxides, and diastereomersthereof, collectively referred to herein as “Compounds of theInvention”.

In another aspect, the Invention provides the use of Compounds of theInvention to treat pain. In certain embodiments, Compounds of theInvention act as blockers of one or more sodium (Na⁺) channels.

In another aspect, the Invention provides a method for treating adisorder responsive to blockade of one or more sodium channels in amammal, comprising administering to the mammal an effective amount of aCompound of the Invention.

Thus, the Invention also provides a method for treating pain (e.g.,acute pain, chronic pain, which includes but is not limited to,neuropathic pain, postoperative pain, and inflammatory pain, or surgicalpain), comprising administering an effective amount of a Compound of theInvention to a mammal in need of such treatment.

In one embodiment, the Invention provides a method for preemptive orpalliative treatment of pain by administering an effective amount of aCompound of the Invention to a mammal in need of such treatment.

Further, the Invention provides a method for treating stroke, neuronaldamage resulting from head trauma, epilepsy, seizures, general epilepsywith febrile seizures, severe myoclonic epilepsy in infancy, neuronalloss following global and focal ischemia, migraine, familial primaryerythromelalgia, paroxysmal extreme pain disorder, cerebellar atrophy,ataxia, dystonia, tremor, mental retardation, autism, aneurodegenerative disorder (e.g., Alzheimer's disease, amyotrophiclateral sclerosis (ALS), or Parkinson's disease), manic depression,tinnitus, myotonia, a movement disorder, or cardiac arrhythmia, orproviding local anesthesia, comprising administering an effective amountof a Compound of the Invention to a mammal in need of such treatment.

In another aspect, the Invention provides a pharmaceutical compositioncomprising a Compound of the Invention and one or more pharmaceuticallyacceptable carriers.

The Invention also provides a pharmaceutical composition for treating adisorder responsive to blockade of one or more sodium ion channels,wherein the pharmaceutical composition comprises an effective amount ofa Compound of the Invention in a mixture with one or morepharmaceutically acceptable carriers.

In a separate aspect, the Invention provides a method of modulating oneor more sodium channels in a mammal, comprising administering to themammal an effective amount of at least one Compound of the Invention.

In still another aspect, the Invention provides a Compound of theInvention for use in treating pain in a mammal, e.g., acute pain,chronic pain, which includes, but is not limited to, neuropathic pain,postoperative pain, and inflammatory pain, or surgical pain.

Moreover, the Invention provides Compounds of the Invention for use intreating stroke, neuronal damage resulting from head trauma, epilepsy,seizures, general epilepsy with febrile seizures, severe myoclonicepilepsy in infancy, neuronal loss following global and focal ischemia,migraine, familial primary erythromelalgia, paroxysmal extreme paindisorder, cerebellar atrophy, ataxia, dystonia, tremor, mentalretardation, autism, a neurodegenerative disorder (e.g., Alzheimer'sdisease, amyotrophic lateral sclerosis (ALS), or Parkinson's disease),manic depression, tinnitus, myotonia, a movement disorder, or cardiacarrhythmia, or providing local anesthesia, in a mammal.

In still another aspect, the Invention provides a radiolabeled Compoundof the Invention and the use of such compounds as radioligands in anyappropriately selected competitive binding assays and screeningmethodologies. Thus, the Invention further provides a method forscreening a candidate compound for its ability to bind to a sodiumchannel or sodium channel subunit using a radiolabeled Compound of theInvention.

In certain embodiments, a Compound of the Invention is radiolabeled with³H, ¹¹C, or ¹⁴C. A competitive binding assay can be conducted using anyappropriately selected methodology. In one embodiment, the screeningmethod comprises: i) introducing a fixed concentration of theradiolabeled compound to an in vitro preparation comprising a soluble ormembrane-associated sodium channel, subunit or fragment under conditionsthat permit the radiolabeled compound to bind to the channel, subunit orfragment, respectively, to form a conjugate; ii) titrating the conjugatewith a candidate compound; and iii) determining the ability of thecandidate compound to displace the radiolabeled compound from saidchannel, subunit or fragment.

In another aspect, the Invention provides a Compound of the Inventionfor use in the manufacture of a medicament for treating pain in amammal. In one embodiment, the Invention provides the use of a Compoundof the Invention in the manufacture of a medicament for palliative orpreemptive treatment of pain, such as, acute pain, chronic pain, orsurgical pain.

A Compound of the Invention can be used in the manufacture of amedicament for treating stroke, neuronal damage resulting from headtrauma, epilepsy, seizures, general epilepsy with febrile seizures,severe myoclonic epilepsy in infancy, neuronal loss following global andfocal ischemia, migraine, familial primary erythromelalgia, paroxysmalextreme pain disorder, cerebellar atrophy, ataxia, dystonia, tremor,mental retardation, autism, a neurodegenarative disorder (e.g.,Alzheimer's disease, amyotrophic lateral sclerosis (ALS), or Parkinson'sdisease), manic depression, tinnitus, myotonia, a movement disorder, orcardiac arrhythmia, or providing local anesthesia, in a mammal.

Additional embodiments and advantages of the Invention will be setforth, in part, in the description that follows, and will flow from thedescription, or can be learned by practice the Invention. Theembodiments and advantages of the Invention will be realized andattained by means of the elements and combinations particularly pointedout in the appended claims.

It is to be understood that both the foregoing summary and the followingdetailed description are exemplary and explanatory only, and are notrestrictive of the Invention as claimed.

DETAILED DESCRIPTION OF THE INVENTION Definitions

Before a further description of the invention, and in order that theinvention may be more readily understood, certain terms are firstdefined and collected herein for convenience.

The term “alkyl” as used by itself or as part of another group refers toa straight- or branched-chain aliphatic hydrocarbon containing one totwelve carbon atoms (i.e., C₁₋₁₂ alkyl) or the number of carbon atomsdesignated (i.e., a C₁ alkyl such as methyl, a C₂ alkyl such as ethyl, aC₃ alkyl such as propyl or isopropyl, etc.). In one embodiment, thealkyl group is chosen from a straight chain C₁₋₁₀ alkyl group. Inanother embodiment, the alkyl group is chosen from a branched chainC₃₋₁₀ alkyl group. In another embodiment, the alkyl group is chosen froma straight chain C₁₋₆ alkyl group. In another embodiment, the alkylgroup is chosen from a branched chain C₃₋₆, alkyl group. In anotherembodiment, the alkyl group is chosen from a straight chain C₁₋₄ alkylgroup. In another embodiment, the alkyl group is chosen from a branchedchain C₃₋₄ alkyl group. In another embodiment, the alkyl group is chosenfrom a straight or branched chain C₃ alkyl group. Non-limiting exemplaryC₁₋₁₀ alkyl groups include methyl, ethyl, propyl, isopropyl, butyl,see-butyl, tert-butyl, iso-butyl, 3-pentyl, hexyl, heptyl, octyl, nonyl,decyl, and the like. Non-limiting exemplary C₁₋₄ alkyl groups includemethyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, andiso-butyl.

The term “optionally substituted alkyl” as used herein by itself or aspart of another group means that the alkyl as defined above is eitherunsubstituted or substituted with one or more (e.g., one, two, or three)substituents independently selected from the group consisting of amino,(alkyl)amino, (alkyl)carbonyl, (aryl)carbonyl, (alkoxy)carbonyl,[(alkoxy)carbonyl]amino, carboxy, aryl, heteroaryl, ureido, guanidino,halogen, sulfonamido, hydroxyl, (alkyl)sulfanyl, nitro, haloalkoxy,aryloxy, aralkyloxy, (alkyl)sulfonyl, (cycloalkyl)sulfonyl,(aryl)sulfonyl, cycloalkyl, sulfanyl, carboxamido, heterocyclyl,(heterocyclyl)sulfonyl, and the like. In one embodiment, the optionallysubstituted alkyl is substituted with two substituents. In anotherembodiment, the optionally substituted alkyl is substituted with onesubstituent. Non-limiting exemplary optionally substituted alkyl groupsinclude —CH(CH₃)CONH₂, —CH₂CH₂NO₂, —CH(OH)CH₂(OH), —CH(OH)CH(OH)CONH₂,—CF₃, —CH₂CH₂CO₂H, —CH₂Ph-OH, —CH₂SH, —CH₂CO₂H, —CH(CH₃)OH,—CH₂CH₂—CH₂NC(═NH)NH₂, —CH₂CH₂SCH₃, —CH₂CH₂COPh, —CH₂C₆H₁₁, and thelike.

As used herein, the term “cycloalkyl” by itself or as part of anothergroup refer to saturated and partially unsaturated (containing one ortwo double bonds) cyclic aliphatic hydrocarbons containing one to threerings having from three to twelve carbon atoms (i.e., C₃₋₁₂ cycloalkyl)or the number of carbons designated. In one embodiment, the cycloalkylgroup has two rings. In one embodiment, the cycloalkyl group has onering. In another embodiment, the cycloalkyl group is a saturated orunsaturated C₃₋₄ cycloalkyl group. In another embodiment, the cycloalkylgroup is a saturated or unsaturated C₅₋₆ cycloalkyl group. Non-limitingexemplary cycloalkyl groups include cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, norbornyl, decalin,adamantyl, cyclohexenyl, cyclopentenyl, cyclohexenyl, and the like.

As used herein, the term “optionally substituted cycloalkyl” by itselfor as pan of another group means that the cycloalkyl as defined above iseither unsubstituted or substituted with one, two, or three substituentsindependently selected from the group consisting of halo, nitro, cyano,hydroxyl, amino, (alkyl)amino, (dialkyl)amino, haloalkyl,(hydroxyl)alkyl, (dihydroxy)alkyl, alkoxy, haloalkoxy, aryloxy,aralkyloxy, alkylthio, carboxamido, sulfonamido, (alkyl)carbonyl.(aryl)carbonyl, (alkyl)sulfonyl, arylsulfonyl, ureido, guanidino,carboxy, (carboxy)alkyl, alkyl, cycloalkyl, alkenyl, alkynyl, aryl,heteroaryl, heterocyclyl, (alkoxy)alkyl, (amino)alkyl,(hydroxyl)alkylamino, (alkylamino)alkyl. (dialkylamino)alkyl,(cyano)alkyl, (carboxamido)alkyl, (alkyl)sulfanyl, (heterocyclo)alkyl,(heteroaryl)alkyl, (alkoxy)carbonyl, mercaptoalkyl, and the like. In oneembodiment, the optionally substituted cycloalkyl is substituted withtwo substituents. In another embodiment, the optionally substitutedcycloalkyl is substituted with one substituent. Non-limiting exemplaryoptionally substituted cycloalkyl groups include:

As used herein, the term “alkenyl” by itself or as part of another grouprefers to an alkyl group as defined above containing one, two or threecarbon-to-carbon double bonds. In one embodiment, the alkenyl group ischosen from a C₂₋₆ alkenyl group. In another embodiment, the alkenylgroup is chosen from a C₂₋₄ alkenyl group. Non-limiting exemplaryalkenyl groups include ethenyl, propenyl, isopropenyl, butenyl,sec-butenyl, pentenyl, and hexenyl.

As used herein, the term “optionally substituted alkenyl” by itself oras part of another group means the alkenyl as defined above is eitherunsubstituted or substituted with one, two or three substituentsindependently selected from the group consisting of halo, nitro, cyano,hydroxyl, amino, (alkyl)amino, (dialkyl)amino, haloalkyl,(hydroxy)alkyl, (dihydroxy)alkyl, alkoxy, haloalkoxy, aryloxy,aralkyloxy, (alkyl)sulfanyl, carboxamido, sulfonamido, (alkyl)carbonyl,(aryl)carbonyl, (alkyl)sulfonyl, (aryl)sulfonyl, ureido, guanidino,carboxy, (carboxy)alkyl, alkyl, cycloalkyl, alkenyl, alkynyl, aryl,heteroaryl, and heterocyclyl.

As used herein, the term “alkynyl” by itself or as part of another grouprefers to an alkyl group as defined above containing one to threecarbon-to-carbon triple bonds. In one embodiment, the alkynyl has onecarbon-to-carbon triple bond. In one embodiment, the alkynyl group ischosen from a C₂₋₆ alkynyl group. In another embodiment, the alkynylgroup is chosen from a C₂₋₄ alkynyl group. Non-limiting exemplaryalkynyl groups include ethynyl, propynyl, butynyl, 2-butynyl, pentynyl,and hexynyl groups.

As used herein, the term “optionally substituted alkynyl” by itself oras part of another group means the alkynyl as defined above is eitherunsubstituted or substituted with one, two or three substituentsindependently selected from the group consisting of halo, nitro, cyano,hydroxyl, amino, alkylamino, dialkylamino, haloalkyl, (hydroxy)alkyl,(dihydroxy)alkyl, alkoxy, haloalkoxy, aryloxy, aralkyloxy,(alkyl)sulfanyl, carboxamido, sulfonamido, alkylcarbonyl, arylcarbonyl,alkylsulfonyl, arylsulfonyl, ureido, guanidino, carboxy, (carboxy)alkyl,alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heterocyclyl, andthe like.

As used herein, the term “haloalkyl” by itself or as part of anothergroup refers to an alkyl group substituted by one or more fluorine,chlorine, bromine and/or iodine atoms. In one embodiment, the alkylgroup is substituted by one, two, or three fluorine and/or chlorineatoms. In another embodiment, the haloalkyl group is chosen from a C₁₋₄haloalkyl group. Non-limiting exemplary haloalkyl groups includefluoromethyl, difluoromethyl, trifluoromethyl, pentafluoroethyl,1,1-difluoroethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl,3,3,3-trifluoropropyl, 4,4,4-trifluorobutyl, and trichloromethyl groups.

As used herein, the term “hydroxyalkyl” or “(hydroxy)alkyl” (also as“(hydroxyl)alkyl”) by itself or as part of another group refers to analkyl group substituted with one hydroxy group, i.e., the hydroxyalkylgroup is a monohydroxyalkyl group. i.e., substituted with one hydroxygroup. In one embodiment, the (hydroxy)alkyl group is chosen from a CIAhydroxyalkyl group. Non-limiting exemplary (hydroxy)alkyl groups include(hydroxy)methyl, (hydroxy)ethyl, (hydroxy)propyl and (hydroxy)butylgroups, such as 1-hydroxylethyl, 2-hydroxylethyl, 2-hydroxylpropyl,3-hydroxylpropyl, 3-hydroxybutyl, 4-hydroxybutyl, and2-hydroxyl-1-methylpropyl.

As used herein, the term “dihydroxyalkyl” or “(dihydroxy)alkyl” byitself or as part of another group refers to an alkyl group substitutedwith two hydroxy groups. e.g.,

Non-limiting exemplary (dihydroxy)alkyl groups include, such as1,2-dihydroxyethyl, and 1,3-dihydroxyprop-2-yl.

As used herein, the terms “(cycloalkyl)alkyl” or “optionally substituted(cycloalkyl)alkyl” by themselves or as part of another group refers toan alkyl group substituted with one, two, or three optionallysubstituted cycloalkyl groups. In one embodiment, the (cycloalkyl)alkylgroup is a CIA alkyl substituted with one optionally substitutedcycloalkyl group. In one embodiment, the (cycloalkyl)alkyl group is a C₁or C₂ alkyl substituted with one optionally substituted cycloalkylgroup. In one embodiment, the (cycloalkyl)alkyl group is a C₁ or C₂alkyl substituted with one cycloalkyl group. Non-limiting exemplarycycloalkyl)alkyl groups include:

As used herein, the term “alkoxy” by itself or as part of another grouprefers to an optionally substituted alkyl, optionally substitutedcycloalkyl, optionally substituted alkenyl, or optionally substitutedalkynyl attached to a terminal oxygen atom. In one embodiment, thealkoxy group is chosen from a C₁₋₄ alkoxy group. In another embodiment,the alkoxy group is chosen from a C₁₋₄ alkyl attached to a terminaloxygen atom, e.g., methoxy, ethoxy, and tert-butoxy.

As used herein, the term “alkoxyalkyl” or “(alkoxy)alkyl” by itself oras part of another group refers to an alkyl group substituted with analkoxy group. Non-limiting exemplary alkoxyalkyl groups includemethoxymethyl, methoxyethyl, methoxypropyl, methoxybutyl, ethoxymethyl,ethoxyethyl, ethoxypropyl, ethoxybutyl, propoxymethyl,iso-propoxymethyl, propoxyethyl, propoxypropyl, butoxymethyl,tert-butoxymethyl, isobutoxymethyl, sec-butoxymethyl, andpentyloxymethyl.

As used herein, the term “haloalkoxy” by itself or as part of anothergroup refers to a haloalkyl attached to a terminal oxygen atom.Non-limiting exemplary haloalkoxy groups include fluoromethoxy,difluoromethoxy, trifluoromethoxy, and 2,2,2-trifluoroethoxy.

As used herein, the term “aryl” by itself or as part of another grouprefers to a monocyclic or bicyclic aromatic ring system having from sixto fourteen carbon atoms (i.e., C₆-C₁₄ aryl). Non-limiting exemplaryaryl groups include phenyl (abbreviated as “Ph”), naphthyl, phenanthryl,anthracyl, indenyl, azulenyl, biphenyl, biphenylenyl, and fluorenylgroups. In one embodiment, the aryl group is chosen from phenyl ornaphthyl.

As used herein, the term “optionally substituted aryl” by itself or aspart of another group means that the aryl as defined above is eitherunsubstituted or substituted with one to five substituents independentlyselected from the group consisting of halo, nitro, cyano, hydroxyl,amino, alkylamino, dialkylamino, haloalkyl, (hydroxy)alkyl,(dihydroxy)alkyl, alkoxy, haloalkoxy, aryloxy, heteroaryloxy,aralkyloxy, alkylthio, carboxamido, sulfonamido, (alkyl)carbonyl,(aryl)carbonyl. (alkyl)sulfonyl, (aryl)sulfonyl, ureido, guanidino,carboxy, carboxyalkyl, alkyl, cycloalkyl, alkenyl, alkynyl, aryl,heteroaryl, heterocyclo. (alkoxy)alkyl, (amino)alkyl,[(hydroxyl)alkyl]amino, [(alkyl)amino]alkyl, [(dialkyl)amino)alkyl,(cyano)alkyl, (carboxamido)alkyl, mercaptoalkyl, (heterocyclo)alkyl,(cycloalkylamino)alkyl, (halo(C₁-C₄)alkoxy)alkyl, (heteroaryl)alkyl, andthe like. In one embodiment, the optionally substituted aryl is anoptionally substituted phenyl. In one embodiment, the optionallysubstituted phenyl has four substituents. In another embodiment, theoptionally substituted phenyl has three substituents. In anotherembodiment, the optionally substituted phenyl has two substituents. Inanother embodiment, the optionally substituted phenyl has onesubstituent. Non-limiting exemplary substituted aryl groups include2-methylphenyl, 2-methoxyphenyl, 2-fluorophenyl, 2-chlorophenyl,2-bromophenyl, 3-methylphenyl, 3-methoxyphenyl, 3-fluorophenyl,3-chlorophenyl, 4-methylphenyl, 4-ethylphenyl, 4-methoxyphenyl,4-fluorophenyl, 4-chlorophenyl, 2,6-di-fluorophenyl,2,6-di-chlorophenyl, 2-methyl, 3-methoxyphenyl, 2-ethyl,3-methoxyphenyl, 3,4-di-methoxyphenyl, 3,5-di-fluorophenyl3,5-di-methylphenyl, 3,5-dimethoxy, 4-methylphenyl,2-fluoro-3-chlorophenyl, and 3-chloro-4-fluorophenyl. The termoptionally substituted aryl is meant to include groups having fusedoptionally substituted cycloalkyl and fused optionally substitutedheterocyclo rings. Examples include:

As used herein, the term “aryloxy” by itself or as part of another grouprefers to an optionally substituted aryl attached to a terminal oxygenatom. A non-limiting exemplary aryloxy group is PhO—.

As used herein, the term “heteroaryloxy” by itself or as part of anothergroup refers to an optionally substituted heteroaryl attached to aterminal oxygen atom. Non-limiting exemplary heteroaryloxy groupsinclude:

As used herein, the term “aralkyloxy” by itself or as part of anothergroup refers to an aralkyl group attached to a terminal oxygen atom. Anon-limiting exemplary aralkyloxy group is PhCH₂O—.

As used herein, the term “heteroaryl” or “heteroaromatic” refers tomonocyclic and bicyclic aromatic ring systems having 5 to 14 ring atoms(i.e., C₅-C₁₄ heteroaryl) and 1, 2, 3, or 4 heteroatoms independentlychosen from oxygen, nitrogen and sulfur. In one embodiment, theheteroaryl has three heteroatoms. In another embodiment, the heteroarylhas two heteroatoms. In another embodiment, the heteroaryl has oneheteroatom. In one embodiment, the heteroaryl is a C₅ heteroaryl. Inanother embodiment, the heteroaryl is a C₆ heteroaryl. Non-limitingexemplary heteroaryl groups include thienyl, benzo[b]thienyl,naphtho[2,3-b]thienyl, thianthrenyl, furyl, benzofuryl, pyranyl,isobenzofuranyl, benzooxazonyl, chromenyl, xanthenyl, 2H-pyrrolyl,pyrrolyl, imidazolyl, pyrazolyl, pyridyl, pyrazinyl, pyrimidinyl,pyridazinyl, isoindolyl, 3H-indolyl, indolyl, indazolyl, purinyl,isoquinolyl, quinolyl, phthalazinyl, naphthyridinyl, cinnolinyl,quinazolinyl, pteridinyl, 4aH-carbazolyl, carbazolyl, β-carbolinyl,phenanthridinyl, acridinyl, pyrimidinyl, phenanthrolinyl, phenazinyl,thiazolyl, isothiazolyl, phenothiazolyl, isoxazolyl, furazanyl, andphenoxazinyl.

In one embodiment, the heteroaryl is chosen from thienyl (e.g.,thien-2-yl and thien-3-yl), furyl (e.g., 2-furyl and 3-furyl), pyrrolyl(e.g., 1H-pyrrol-2-yl and 1H-pyrrol-3-yl), imidazolyl (e.g.,2H-imidazol-2-yl and 2H-imidazol-4-yl), pyrazolyl (e.g.,1H-pyrazol-3-yl, 1H-pyrazol-4-yl, and III-pyrazol-5-yl), pyridyl (e.g.,pyridin-2-yl, pyridin-3-yl, and pyridin-4-yl), pyrimidinyl (e.g.,pyrimidin-2-yl, pyrimidin-4-yl, and pyrimidin-5-yl), thiazolyl (e.g.,thiazol-2-yl, thiazol-4-yl, and thiazol-5-yl), isothiazolyl (e.g.,isothiazol-3-yl, isothiazol-4-yl, and isothiazol-5-yl), oxazolyl (e.g.,oxazol-2-yl, oxazol-4-yl, and oxazol-5-yl) and isoxazolyl (e.g.,isoxazol-3-yl, isoxazol-4-yl, and isoxazol-5-yl). The term “heteroaryl”is also meant to include possible N-oxides. Exemplary N-oxides includepyridyl N-oxide and the like.

As used herein, the ten “optionally substituted heteroaryl” by itself oras part of another group means that the heteroaryl as defined above iseither unsubstituted or substituted with one to four substituents, e.g.,one or two substituents, independently selected from the groupconsisting of halo, nitro, cyano, hydroxy, amino, (alkyl)amino,(dialkyl)amino, haloalkyl, (hydroxy)alkyl, (dihydroxy)alkyl, alkoxy,haloalkoxy, aryloxy, aralkyloxy, alkylthio, carboxamido, sulfonamido,(alkyl)carbonyl, (aryl)carbonyl, (alkyl)sulfonyl, (aryl)sulfonyl,ureido, guanidino, carboxy, (carboxy)alkyl, alkyl, cycloalkyl, alkenyl,alkynyl, aryl, heteroaryl, heterocyclo, (alkoxy)alkyl, (amino)alkyl,[(hydroxyl)alkyl]amino, [(alkyl)amino]alkyl, [(dialkyl)amino]alkyl,(cyano)alkyl, (carboxamido)alkyl, mercaptoalkyl, (heterocyclo)alkyl,(heteroaryl)alkyl, and the like. In one embodiment, the optionallysubstituted heteroaryl has one substituent. In one embodiment, theoptionally substituted is an optionally substituted pyridyl, i.e., 2-,3-, or 4-pyridyl. Any available carbon or nitrogen atom can besubstituted. In another embodiment, the optionally substitutedheteroaryl is an optionally substituted indole.

As used herein, the term “heterocyclo” or “heterocyclyl” by itself or aspart of another group refers to saturated and partially unsaturated(e.g., containing one or two double bonds) cyclic groups containing one,two, or three rings having from three to fourteen ring members (i.e., a3- to 14-membered heterocyclo) and at least one heteroatom. Eachheteroatom is independently selected from the group consisting ofoxygen, sulfur, including sulfoxide and sulfone, and/or nitrogen atoms,which can be quaternized. The term “heterocyclo” or “heterocyclyl” ismeant to include cyclic ureido groups, such as, 2-imidazolidinone, andcyclic amide groups, such as, β-lactam, γ-lactam, δ-lactam and ε-lactam.The term “heterocyclo” or “heterocyclyl” is also meant to include groupshaving fused optionally substituted aryl groups, e.g., indolinyl. In oneembodiment, the heterocyclo or heterocyclyl group is chosen from a 5- or6-membered cyclic group containing one ring and one or two oxygen and/ornitrogen atoms. The heterocyclo or heterocyclyl can be optionally linkedto the rest of the molecule through a carbon or nitrogen atom.Non-limiting exemplary heterocyclo (or heterocyclyl) groups include2-oxopyrrolidin-3-yl, 2-imidazolidinone, piperidinyl, morpholinyl,piperazinyl, pyrrolidinyl, and indolinyl.

As used herein, the term “optionally substituted heterocyclo” or“optionally substituted heterocyclyl” by itself or part of another groupmeans the heterocyclo or heterocyclyl group as defined above is eitherunsubstituted or substituted with one to four substituents independentlyselected from the group consisting of halo, nitro, cyano, hydroxyl,amino, (alkyl)amino. (dialkyl)amino, haloalkyl, (hydroxy)alkyl,(dihydroxy)alkyl, alkoxy, haloalkoxy, aryloxy, aralkyloxy, alkylthio,carboxamido, sulfonamido, (alkyl)carbonyl, (aryl)carbonyl,(alkyl)sulfonyl, (aryl)sulfonyl, ureido, guanidino, carboxy,carboxyalkyl, alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl,heterocyclyl, alkoxyalkyl, (amino)alkyl, [(hydroxyl)alkyl]amino,[(alkyl)amino]alkyl, [(dialkyl)amino]alkyl, (cyano)alkyl,(carboxamido)alkyl, mercaptoalkyl, (heterocyclyl)alkyl,(heteroaryl)alkyl, and the like. Substitution may occur on any availablecarbon or nitrogen atom, and may form a spirocycle. Non-limitingexemplary optionally substituted heterocyclyl groups include:

As used herein, the term “amino” by itself or as part of another grouprefers to —NH₂.

As used herein, the term “alkylamino” or “(alkyl)amino” by itself or aspart of another group refers to —NHR¹⁵, wherein R¹⁵ is alkyl.

As used herein, the term “dialkylamino” or “(dialkylamino” by itself oras part of another group refers to —NR^(16a)R^(16b), wherein R^(16a) andR^(16b) are each independently alkyl or R^(16a) and R^(16b) are takentogether to form a 3- to 8-membered optionally substituted heterocyclo.

As used herein, the term “hydroxyalkylamino” by itself or as part ofanother group refers to —NHR¹⁷, wherein R¹⁷ is hydroxyalkyl.

As used herein, the term “cycloalkylamino” by itself or as part ofanother group refers to —NR^(19a)R^(19b), wherein R^(19a) is optionallysubstituted cycloalkyl and R^(19b) is hydrogen or alkyl.

As used herein, the term “(amino)alkyl” by itself or as part of anothergroup refers to an alkyl group substituted with an amino group.Non-limiting exemplary amino alkyl groups include —CH₂CH₂NH₂,—CH₂CH₂CH₂NH₂, —CH₂CH₂CH₂CH₂NH₂ and the like.

As used herein, the term “(alkylamino)alkyl” or “[(alkyl)amino]alkyl” byitself or as part of another group refers to an alkyl group substitutedwith an alkylamino group. A non-limiting exemplary (alkylamino)alkylgroup is —CH₂CH₂N(H)CH₃.

As used herein, the term “(dialkylamino)alkyl” or“[(dialkyl)amino]alkyl” by itself or as part of another group refers toan alkyl group substituted by a dialkylamino group. Non-limitingexemplary [(dialkyl)amino]alkyl groups include —CH₂N(CH₃)₂ and—CH₂CH₂N(C₁₋₃)₂.

As used herein, the term “(cycloalkylamino)alkyl” by itself or as partof another group refers to an alkyl group substituted by acycloalkylamino group. Non-limiting exemplary (cycloalkylamino)alkylgroups include —CH₂N(H)cyclopropyl, —CH₂N(H)cyclobutyl, and—CH₂N(H)cyclohexyl.

As used herein, the term “(halo(C₁₋₃)alkoxy)alkyl” by itself or as partof another group refers to an alkyl group substituted by ahalo(C₁₋₃)alkoxy group. Non-limiting exemplary (halo(C₁₋₃)alkoxy)alkylgroups include —CH₂OCH₂CF₃ and —CH₂OCF₃.

As used herein, the term “(cyano)alkyl” by itself or as part of anothergroup refers to an alkyl group substituted with one or more cyano, e.g.,—CN, groups. Non-limiting exemplary (cyano)alkyl groups include—CH₂CH₂CN, —CH₂CH₂CH₂CN, and —CH₂CH₂CH₂CH₂CN.

As used herein, the term “carboxamido” by itself or as part of anothergroup refers to a radical of formula —C(═O)NR^(24a)R^(24b), whereinR^(24a) and R^(24b) are each independently hydrogen, optionallysubstituted alkyl, optionally substituted aralkyl, optionallysubstituted aryl, or optionally substituted heteroaryl, or R^(24a) andR^(24b) taken together with the nitrogen to which they are attached froma 3- to 8-membered heterocyclo group. In one embodiment, R^(24a) andR^(24b) are each independently hydrogen or optionally substituted alkyl.Non-limiting exemplary carboxamido groups include —CONH₂, —CON(H)CH₃,—CON(CH₃)₂, and CON(H)Ph.

As used herein, the term “sulfonamido” by itself or as part of anothergroup refers to a radical of the formula —SO₂NR^(23a)R^(23b), whereinR^(23a) and R^(23b) are each independently hydrogen, optionallysubstituted alkyl, or optionally substituted aryl, or R^(23a) andR^(23b) taken together with the nitrogen to which they are attached froma 3- to 8-membered heterocyclo group. Non-limiting exemplary sulfonamidogroups include —SO₂NH₂, —SO₂N(H)CH₃, and —SO₂N(H)Ph.

As used herein, the term “(alkyl)carbonyl” by itself or as part ofanother group refers to a carbonyl group, i.e., —C(═O)—, substituted byan alkyl group. A non-limiting exemplary alkylcarbonyl group is —COCH₃.

As used herein, the term “(alkoxy)carbonyl” (or “ester”) by itself or aspart of another group refers to a carbonyl group, i.e., —C(═O)—,substituted by an alkoxy group. A non-limiting exemplary(alkoxy)carbonyl group is —C(O)OCH₃.

As used herein, the term “(aryl)carbonyl” by itself or as part ofanother group refers to a carbonyl group, i.e., —C(═O)—, substituted byan optionally substituted aryl group. A non-limiting exemplaryarylcarbonyl group is —COPh.

As used herein, the term “sulfanyl” by itself or as part of anothergroup refers to a —SH group.

The term “(alkyl)sulfanyl” or “alkylthio” by itself or as part ofanother group refers to a sulfur atom substituted by an optionallysubstituted alkyl group. In one embodiment, the alkylthio group ischosen from a C₁₋₄ alkylthio group. Non-limiting exemplary alkylthiogroups include —SCH₃, and —SCH₂CH₃.

The term “mercaptoalkyl” as used herein by itself or as part of anothergroup refers to any of the above-mentioned alkyl groups substituted by a—SH group.

As used herein, the term “alkylsulfonyl” or “(alkyl)sulfonyl” by itselfor as part of another group refers to a sulfonyl group, i.e., —SO₂—,substituted by any of the above-mentioned optionally substituted alkylgroups. A non-limiting exemplary alkylsulfonyl group is —SO₂CH₁.

As used herein, the term “arylsulfonyl” or “(aryl)sulfonyl” by itself oras part of another group refers to a sulfonyl group, i.e., —SO₂—,substituted by any of the above-mentioned optionally substituted arylgroups. A non-limiting exemplary arylsulfonyl group is —SO₂Ph.

As used herein, the term “carboxy” by itself or as part of another grouprefers to a radical of the formula —COOH.

As used herein, the term “(carboxy)alkyl” by itself or as part ofanother group refers to any of the above-mentioned alkyl groupssubstituted with a —COOH. A non-limiting exemplary carboxyalkyl group is—CH₂CO₂H.

As used herein, the terms “aralkyl” or “arylalkyl” or “optionallysubstituted aralkyl” by themselves or as part of another group refers toan alkyl group substituted with one, two, or three optionallysubstituted aryl groups. In one embodiment, the optionally substitutedaralkyl group is a C₁ alkyl substituted with one optionally substitutedaryl group. In one embodiment, the optionally substituted aralkyl groupis a C₁ or C₂ alkyl substituted with one optionally substituted arylgroup. In one embodiment, the optionally substituted aralkyl group is aC₁ or C₂ alkyl substituted with one optionally substituted phenyl group.Non-limiting exemplary optionally substituted aralkyl groups includebenzyl, phenethyl, —CHPh₂, —CH₂(4-F-Ph), —CH₂(4-Me-Ph), —CH₂(4-CF₃-Ph),and —CH(4-F-Ph)₂.

As used herein, the term “ureido” by itself or as part of another grouprefers to a radical of the formula —NR^(22a)—C(═O)—NR^(22b)R^(22c),wherein R^(22a) is hydrogen, alkyl, or optionally substituted aryl, andR^(22b) and R^(22c) are each independently hydrogen, alkyl, oroptionally substituted aryl, or R^(22b) and R^(22c) taken together withthe nitrogen to which they are attached form a 4- to 8-memberedheterocyclo group. Non-limiting exemplary ureido groups include—NH—C(═O)—NH₂ and —NH—C(═O)—NHCH₃.

For As used herein, the term “guanidino” by itself or as part of anothergroup refers to a radical of the formula—NR^(25a)—C(═NR²⁶)—NR^(25b)R^(25c), wherein R^(25a), R^(25b), andR^(25c) are each independently hydrogen, alkyl, or optionallysubstituted aryl, and R²⁶ is hydrogen, alkyl, cyano, alkylsulfonyl,alkylcarbonyl, carboxamido, or sulfonamido. Non-limiting exemplaryguanidino groups include —NH—C(═NH)—NH₂, —NH—C(═NCN)—NH₂,—NH—C(═NH)—NHCH₃ and the like.

As used herein, the terms “(heteroaryl)alkyl” or “optionally substituted(heteroaryl)alkyl” by themselves or as part of another group refers toan alkyl group substituted with one, two, or three optionallysubstituted heteroaryl groups. In one embodiment, the (heteroaryl)alkylgroup is a CIA alkyl substituted with one optionally substitutedheteroaryl group. In one embodiment, the (heteroaryl)alkyl is a C₁ or C₂alkyl substituted with one optionally substituted heteroaryl group.Non-limiting exemplary (heteroaryl)alkyl groups include:

The term “heteroalkyl” as used herein by itself or part of another grouprefers to a stable straight or branched chain hydrocarbon radicalcontaining 1 to 10 carbon atoms and at least two heteroatoms, which canbe the same or different, selected from O, N, or S, wherein: 1) thenitrogen atom(s) and sulfur atom(s) can optionally be oxidized; and/or2) the nitrogen atom(s) can optionally be quaternized. The heteroatomscan be placed at any interior position or terminal position of theheteroalkyl group, or at a position at which the heteroalkyl group isattached to the remainder of the molecule. In one embodiment, theheteroalkyl group contains two oxygen atoms. In another embodiment, theheteroalkyl group contains two nitrogen atoms. In other embodiment, theheteroalkyl group contains one nitrogen atom and one oxygen atom.Non-limiting exemplary heteroalkyl groups include:—CH₂N(H)CH₂CH₂N(CH₃)₂; —CH₂N(CH₃)CH₂CH₂N(CH₃)₂;—CH₂N(H)CH₂CH₂CH₂N(CH₃)₂; —CH₂N(H)CH₂CH₂OH; —CH₂N(CH₃)CH₂CH₂OH:—CH₂OCH₂CH₂OCH₃, —OCH₂CH₂OCH₂CH₂OCH₃: —CH₂NHCH₂CH₂OCH₂; —OCH₂CH₂NH₂; and—NHCH₂CH₂N(H)CH₃.

As used herein, the term “(heterocyclo)alkyl” or “(heterocyclyl)alkyl”by itself or as part of another group refers to an alkyl groupsubstituted with one optionally substituted heterocyclyl group, andoptionally one hydroxyl group. In one embodiment, the(heterocyclyl)alkyl is a C₁₋₄ alkyl substituted with one optionallysubstituted heterocyclyl group and one hydroxy group. In anotherembodiment, the (heterocyclo)alkyl (or (heterocyclyl)alkyl) is a C₁₋₄alkyl substituted with one optionally substituted heterocyclo orheterocyclyl group. Non-limiting exemplary (heterocyclo)alkyl or(heterocyclyl)alkyl groups include:

As used herein, the term “(carboxamido)alkyl” by itself or as part ofanother group refers to an alkyl group substituted with one carboxamidogroup, and optionally one heterocyclo, amino, alkylamino, ordialkylamino group. In one embodiment, the (carboxamido)alkyl is a C₁₋₄alkyl substituted with one carboxamido group, and optionally oneheterocyclo, amino, alkylamino, or dialkylamino group. In anotherembodiment, the (carboxamido)alkyl is a C₁₋₄ alkyl substituted with onecarboxamido group and one heterocyclo, amino, alkylamino, ordialkylamino group. In another embodiment, the (carboxamido)alkyl is aC₁₋₄ alkyl substituted with one carboxamido group. Non-limitingexemplary (carboxamido)alkyl groups include —CH₂CON₂, —C(H)CH—CONH₂,—CH₂CON(H)CH₃,

The term “N-oxide” as used herein refers to a compound that contains aN⁺—O⁻ functional group, wherein N⁺ is further connected to H and/or therest of the compound structure.

As used herein, the term “stereoisomers” is a general term for allisomers of individual molecules that differ only in the orientation oftheir atoms in space. It includes enantiomers and isomers of compoundswith more than one chiral center that are not mirror images of oneanother (diastereomers).

The term “chiral center” refers to a carbon atom to which four differentgroups are attached.

The terms “enantiomer” and “enantiomeric” refer to a molecule thatcannot be superimposed on its mirror image and hence is optically activewherein the enantiomer rotates the plane of polarized light in onedirection and its mirror image compound rotates the plane of polarizedlight in the opposite direction.

The term “racemic” refers to a mixture of equal parts of enantiomers andwhich mixture is optically inactive.

The term “resolution” refers to the separation or concentration ordepletion of one of the two enantiomeric forms of a molecule.

The terms “a” and “an” refer to one or more.

The term “treat,” “treating” or “treatment” is meant to encompassadministering to a subject a compound of the Invention for the purposesof amelioration or cure, including preemptive and palliative treatment.In one embodiment, the term “treat,” “treating” or “treatment” is meantto encompass administering to a subject a compound of the Invention forthe purposes of amelioration or cure.

The term “about,” as used herein in connection with a measured quantity,refers to the normal variations in that measured quantity, as expectedby the skilled artisan making the measurement and exercising a level ofcare commensurate with the objective of measurement and the precision ofthe measuring equipment.

LIST OF ABBREVIATIONS

-   -   ACN acetonitrile    -   AcOH acetic acid    -   aq. aqueous    -   atm atmosphere(s)    -   Boc tert-butoxycarbonyl    -   ° C. degrees Celsius    -   conc. concentrated    -   DCM dichloromethane    -   DIPEA diisopropylethylamine    -   DME 1,2-dimethoxyethane    -   DMF dimethylformamide    -   DMSO dimethylsulfoxide    -   Et₂O diethyl ether    -   EtOAc ethyl acetate    -   EtOH ethanol    -   h hour(s)    -   HPLC high pressure liquid chromatography    -   i-PrOH iso-propanol    -   MeOH methanol    -   min minute(s)    -   Pd/C palladium on carbon    -   Pd(dppf)Cl₂ [1,1′-bis(diphenylphosphino)ferrocene]palladium(II)        dichloride    -   Pd(PPh₃)₂Cl₂ bis(triphenylphosphine)palladium(1) dichloride    -   psi pounds per square inch    -   RT mom temperature    -   satd. saturated    -   t-BuOH tert-butyl alcohol    -   TEA triethylamine    -   TFA trifluoroacetic acid    -   THF tetrahydrofuran

DETAILED DESCRIPTION OF THE INVENTION Compounds of the Invention

The Invention provides compounds as delineated infra. In one aspect, theCompounds of the Invention are useful in treating pain. Without wishingto be bound by any theory, it is believed that the Compounds of theInvention can act as blockers of one or more sodium (Na⁺) channels whiletreating pain. In certain embodiments, the Compounds of the Inventionare useful for treating disorders responsive to the blockade of one ormore sodium ion channels.

In one aspect, the Invention provides a compound of Formula I, or apharmaceutically acceptable salt, solvate, hydrate, N-oxide, ordiastereomer thereof:

Wherein

a and b, each independently, are 0, 1, or 2, provided that at least oneof a and b is a value other than 0;

n, each independently, is 0, 1, or 2;

m, each independently, is 0, 1, or 2;

k, each independently, is 1, 2, or 3;

W¹, W², and W³, each independently, are CR⁶ or N, provided that at leastone of W¹, W² and W³ is N;

One of R¹ and R² is H, cyano, —C(O)N(R)(R^(b)), —S(O)₂N(R^(a))(R^(b)),—C(O)OR⁷, —OC(O)R⁷, —OR⁷, —[CH(R^(c))]_(n)R⁸, or —N(R^(d))(R^(e)), theother is selected from the group consisting of H, —C(O)N(R^(a))(R^(b)),—S(O)₂N(R^(a))R^(b)), —C(O)OR⁷, —OC(O)R⁷, —OR⁷, —[CH(R^(c))]_(n)R⁸,—N(R^(d))(R^(e)), —S(O)_(m)—R^(f), ureido, halogen, cyano, and nitro;provided that R¹ and R² cannot be both H;

R³ is H, alkyl, haloalkyl, —S(O)_(m)—R^(f), alkoxy, haloalkoxy,carboxamido, cyano, (carboxamido)alkyl, (hydroxy)alkyl,(dihydroxy)alkyl, nitro, optionally-substituted cycloalkyl,optionally-substituted heterocyclyl, (heterocyclyl)amino, sulfonamido,[(heterocyclyl)amino]alkyl. (alkoxy)alkyl, optionally-substituted aryl,or optionally-substituted heteroaryl, provided that when a is 2 and b is0, then R³ is a group other than H;

R⁴ and R⁵, each independently, are H, alkyl, haloalkyl, —S(O)_(m)—R^(f),alkoxy, haloalkoxy, amino, (alkyl)amino, (dialkyl)amino, carboxamido,cyano, hydroxyl, halogen, (hydroxy)alkyl, (dihydroxy)alkyl, nitro, orsulfonamido;

R⁶, each independently, is H, alkyl, hydroxyl, (hydroxyl)alkyl,(dihydroxy)alkyl, amino, (alkyl)amino, (dialkyl)amino, haloalkyl,alkoxy, carboxamido, or sulfonamido:

J¹ is absent, —S(O)₂—, —C(O)—, or —(CHR⁹)_(k)—;

J² is absent. —S(O)₂—, or —C(O)—;

A is selected from the group consisting of

-   -   a) optionally-substituted alkyl;    -   b) optionally-substituted alkoxy;    -   c) optionally-substituted aryl;    -   d) optionally-substituted heteroaryl;    -   e) optionally-substituted cycloalkyl;    -   f) optionally-substituted heterocyclyl; and    -   g) —N(R¹⁰)(R¹¹);

R⁷, each independently, is H, optionally-substituted alkyl,optionally-substituted cycloalkyl, or optionally-substitutedheterocyclyl;

R⁸, each independently, is H, optionally-substituted alkyl,optionally-substituted cycloalkyl, optionally-substituted heterocyclyl,or —C(O)N(R¹²)(R¹³);

R⁹, each independently, is H or optionally-substituted alkyl;

R¹⁰ and R¹¹, each independently, are H, optionally-substituted alkyl,optionally-substituted (alkyl)carbonyl, optionally-substituted(cycloalkyl)carbonyl, optionally-substituted (heterocyclyl)carbonyl,optionally-substituted heterocyclyl, or optionally-substitutedcycloalkyl, provided that R¹⁰ and R¹¹ cannot be both H;

or R¹⁰ and R¹¹, taken together with the nitrogen atom to which they areattached, form a 3- to 8-membered optionally substituted heterocyclyl;

One of R¹² and R¹³ is H, the other is H, optionally-substituted alkyl,optionally-substituted heterocyclyl, or optionally-substitutedcycloalkyl; or R¹² and R¹³, taken together with the nitrogen atom towhich they are attached, form a 3- to 8-membered optionally substitutedheterocyclyl;

R^(a), on each occurrence, independently is H, optionally-substitutedalkyl, optionally-substituted heterocyclyl, optionally-substituted aryl,optionally-substituted cycloalkyl, or optionally-substituted heteroaryl;

R^(b), on each occurrence, independently is H, optionally-substitutedalkyl, optionally-substituted heterocyclyl, optionally-substituted aryl,optionally-substituted cycloalkyl, or optionally-substituted heteroaryl;

Or R^(a) and R^(b), taken together with the nitrogen atom to which theyboth are attached, form a 3- to 8-membered optionally substitutedheterocyclyl; R, each independently, is H, hydroxyl, or alkoxy;

R^(d) and R^(e), each independently, are H, carboxamido,optionally-substituted (alkyl)carbonyl, optionally-substituted alkyl,optionally-substituted heterocyclyl, optionally-substituted(heterocycyl)carbonyl, optionally-substituted aryl,optionally-substituted cycloalkyl, optionally-substituted(alkyl)sulfonyl, or optionally-substituted heteroaryl; or R^(d) andR^(e), taken together with the nitrogen atom to which they both areattached, form a 3- to 8-membered optionally substituted heterocyclyl;and

R^(f), each independently, is optionally-substituted alkyl,optionally-substituted cycloalkyl, or optionally-substitutedheterocyclyl;

Provided that

when J² is absent and A is optionally-substituted alkyl, then saidoptionally-substituted alkyl is unsubstituted or substituted by one tothree substituents independently selected from the group consisting ofamino, (alkyl)carbonyl, (aryl)carbonyl, (alkoxy)carbonyl, carboxy, aryl,heteroaryl, ureido, guanidino, halogen, sulfonamido, hydroxyl,(alkyl)sulfanyl, haloalkoxy, cycloalkyl, (alkyl)sulfonyl, andcarboxamido.

In one embodiment of Formula I, a is 1. In another embodiment of FormulaI, b is 1. One example provides that a is 1, and b is 1 in Formula I.

In certain embodiments of Formula I, J¹ is absent. In separateembodiments of Formula I, J² is absent.

In one embodiment, Compounds of the Invention are compounds representedby Formula I, wherein W³ is CR⁶, and pharmaceutically acceptable salts,solvates, hydrates, N-oxides, or diastereomers thereof. In oneembodiment, W³ is CH. One embodiment provides that W² is N and W³ is CH.Another embodiment provides that both of W² and W³ are N.

In another embodiment, Compounds of the Invention are compoundsrepresented by Formula I, wherein W³ is N and pharmaceuticallyacceptable salts, solvates, hydrates, N-oxides, or diastereomersthereof. One embodiment provides that W² is N and W³ is CH. Anotherembodiment provides that both of W² and W³ are CH.

Certain embodiments of the Invention provide compounds represented byFormula II and pharmaceutically acceptable salts, solvates, hydrates.N-oxides, or diastereomers thereof:

Wherein

n is 0, 1, or 2;

W¹, W², and W³, each independently, are CH or N, provided that at leastone of W¹, W² and W³ is N;

A is selected from the group consisting of phenyl, 5- to 6-memberedheteroaryl, and saturated or unsaturated cyclo(C₅₋₆)alkyl, wherein eachof said phenyl, said 5- to 6-membered heteroaryl, and said saturated orunsaturated cyclo(C₅₋₆)alkyl is optionally substituted by one or twosubstituents independently selected from the group of

i) alkyl (e.g., (C₁₋₆)alkyl) optionally substituted by one or threesubstituents independently selected from the group of halogen, amino,(alkyl)amino, (dialkyl)amino, hydroxyl, carboxamido, (alkoxy)carbonyl,[(alkoxy)carbonyl]amino, carboxy, alkoxy, haloalkoxy,optionally-substituted cycloalkyl, optionally-substituted heterocyclyl,and sulfonamido, wherein said cycloalkyl and said heterocyclyl, eachindependently, are optionally substituted by one or two substituentsindependently selected from the group consisting of hydroxyl, halogen,amino, (alkyl)amino, carboxamido, alkyl, haloalkyl, carboxy,(carboxy)alkyl, (carboxamido)alkyl, (alkyl)carbonyl, (alkoxy)carbonyl,and alkoxy;

ii) amino optionally substituted by one to two substituentsindependently selected from the group consisting of alkyl,(carboxamido)alkyl, (amino)alkyl, (alkyl)carbonyl, (alkyl)sulfonyl,(alkoxy)carbonyl, (cycloalkyl)carbonyl, cycloalkyl, and heterocyclyl;

iii) alkoxy (e.g., (C₁₋₆)alkoxy) optionally substituted by one to threesame or different halogen;

iv) carboxamido;

v) hydroxyl;

vi) halogen; and

vii) sulfonamido;

One of R and R² is H, —C(O)N(R^(a))(R^(b)), or —[CH(OH)]^(n)R⁸, theother is H, —C(O)N(R^(a))(R^(b)), —N(R^(d))(R^(c)), —[CH(OH)]_(n)R⁸,—S(O)₂N(R^(a))(R^(b)), —OR⁷, or —CH₂—R⁸, provided that R¹ and R² cannotbe both H;

R³ is H, alkyl, haloalkyl, alkoxy, haloalkoxy, carboxamido,(hydroxy)alkyl, (dihydroxy)alkyl, or sulfonamido;

R⁴ and R⁵, each independently, are H, alkyl, haloalkyl, alkoxy,haloalkoxy, amino, (alkyl)amino, (dialkyl)amino, carboxamido, hydroxyl,halogen. (hydroxyl)alkyl, (dihydroxyl)alkyl, or sulfonamido;

R⁷ is optionally-substituted cycloalkyl, or optionally-substitutedheterocyclyl;

R⁸ is H, alkyl, optionally-substituted heterocyclyl, or—C(O)N(R¹²)(R¹³);

R^(a), each independently, is H, optionally-substituted alkyl,optionally-substituted heteroaryl, or optionally-substitutedheterocyclyl;

R^(b), each independently, is H, optionally-substituted alkyl,optionally-substituted heteroaryl, or optionally-substitutedheterocyclyl;

or R^(a) and R^(b), taken together with the nitrogen atom to which theyboth are attached, form a 3- to 8-membered optionally-substitutedheterocyclyl;

R^(d) and R^(e), each independently, are selected from the group of

1) H;

2) alkyl optionally substituted by one or three substituentsindependently selected from the group of amino, (alkyl)amino,(alkyl)carbonyl, (alkoxy)carbonyl, carboxy, optionally-substituted aryl,optionally-substituted heteroaryl, ureido, guanidino, halogen, hydroxyl,(alkyl)sulfanyl, sulfanyl, and carboxamido;

3) heterocyclyl optionally substituted by one or two substituentsindependently selected from the group of halogen, alkyl, amino,(alkyl)amino, (alkyl)carbonyl, carboxy, (alkoxy)carbonyl, andcarboxamido;

4) (alkyl)carbonyl optionally substituted by one or two substituentsindependently selected from the group of amino, hydroxyl, and alkoxy;and

5) (alkyl)sulfonyl optionally substituted by one or two substituentsindependently selected from the group of halogen, optionally-substitutedheterocyclyl, and alkoxy; or R^(d) and R^(c), taken together with thenitrogen atom to which they both are attached, form a 5- to 6-memberedoptionally substituted heterocyclyl; and

One of R¹² and R¹³ is H, the other is H or alkyl.

As one embodiment in accordance with Formula I or II, the Inventionprovides that R³, R⁴, and R⁵ are all H.

In certain embodiments of Formula I or II, at least one of R¹ and R² isH. —C(O)N(R^(a)(R^(b)) or —[CH(OH)]_(n)R⁸. For example, R¹ is H,—C(O)N(R^(a))(R^(b)) or —[CH(OH)]_(n)R⁸, and R² is selected from thegroup consisting of H, —C(O)N(R^(a))(R^(b)), —N(R^(d))(R^(e)),—[CH(OH)]_(n)R⁸, —S(O)₂N(R^(a))(R^(b)), —OR⁷, and —CH₂—R⁸.Alternatively, R² is H, —C(O)N(R^(a))(R^(b)) or —[CH(OH)]_(n)R⁸, and R¹is selected from the group consisting of H, —C(O)N(R^(a))(R^(b)),—N(R^(d))(R^(e)), —[CH(OH)]_(n)R⁸, —S(O)₂N(R^(a))(R^(b)), —OR⁷, and—CH₂—R⁸.

In one embodiment, Compounds of the Invention are compounds representedby Formula I or II, wherein R¹ is H or —C(O)N(R^(a))(R^(b)), andpharmaceutically acceptable salts, solvates, hydrates, N-oxides, ordiastereomers thereof. One embodiment provides that R¹ is—C(O)N(R^(a))(R^(b)), wherein one of R¹ and R is H, the other is H or(C₃)alkyl (e.g., methyl, ethyl, propyl, or isopropyl). One exampleprovides that R¹ is —C(O)NH₂ in accordance with Formula I or II. Undercertain circumstances, R² is selected from the group consisting of H,—N(R^(d))(R^(e)), —[CH(OH)]₂R⁸, —OR⁷, —S(O)N(R^(a))(R^(b)), and —CH₂—R⁸.It is understood that R¹ and R² cannot be both H.

In another embodiment, Compounds of the Invention are compoundsrepresented by Formula I or II, wherein R¹ is H, and pharmaceuticallyacceptable salts, solvates, hydrates, N-oxides, or diastereomersthereof. One embodiment provides that R² is selected from the groupconsisting of H, —N(R^(d))(R^(e)), —[CH(OH)]₂R⁸, —OR⁷,—S(O)₂N(R^(a))(R^(b)), and —CH₂—R⁸. It is understood that R¹ and R²cannot be both H.

In accordance with any one of the above embodiments of Formula I or II,R¹ is —N(R^(d))(R^(e)). In one embodiment, R² is —N(R^(d))(R^(e)), oneof R^(d) and R^(e) is H, the other is selected from the group consistingof:

Wherein

y is 0, 1, 2, 3, or 4;

x is 1, 2, or 3:

R¹⁴ is H or optionally-substituted (C₁₋₆)alkyl, wherein saidoptionally-substituted (C₁₋₆) alkyl is optionally substituted by—S(C₁₋₃alkyl), hydroxyl, —SH, —C(O)NH₂, —C(O)OH, —NHC(═NH)NH₂, amino,heteroaryl, or aryl, wherein said aryl is further optionally substitutedby hydroxyl or (C₁₋₃)alkoxy;

R^(2a) and R^(2b), each independently, are H or (C₁₋₆)alkyl;

or R^(2a) and R^(2b), taken together with the nitrogen atom to whichthey are attached, form a 3- to 8-membered heterocyclyl optionallysubstituted one or two substituents independently selected from thegroup of alkyl, haloalkyl, (alkoxy)carbonyl, amino, alkoxy, andcarboxamido.

In an alternative embodiment, R² is —N(R^(d))(R^(e)), and one of R^(d)and R^(e) is H, the other is the other is (C₁₋₆alkyl)carbonyl optionallysubstituted by one or two hydroxyl groups. Non-limiting exemplary(C₁₋₆alkyl)carbonyl groups as referred to herein include thoseillustrated as follows:

A separate embodiment provides that R² is —N(R^(d))(R^(e)), and R^(d)and R^(e), taken together with the nitrogen atom to which they both areattached, form an optionally substituted 5- to 6-membered heterocyclyl.Non-limiting exemplary 5- to 6-membered heterocyclyl groups includethose illustrated as follows:

Further, any of the above-mentioned 5- to 6-membered heterocyclyl groupscan be optionally substituted by one or two same or differentsubstituents selected from the group of hydroxyl, carboxamido,(C₁₋₃)alkoxy, (C₁₋₃)alkyl, (C₁₋₃alkyl)carbonyl, and halo(C₁₋₃)alkyl.

In an alternative embodiment of Formula I or II, R² is —OR⁷. Oneembodiment provides that R⁷ is heterocyclyl selected from the groupconsisting of:

wherein u is 1, 2, or 3. In certain embodiments, the heterocyclyl groupas R⁷ can be further optionally substituted by one, two, or three sameor different substituents as above defined, including, such as,hydroxyl, carboxamido, (C₁₋₃)alkoxy. (C₁₋₃)alkyl, (C₁₋₃alkyl)carbonyl,and halo(C₁₋₃)alkyl.

In another embodiment of Formula I or II, R is —[CH(OH)]₂R⁸. Oneembodiment provides that R⁸ is H. Another embodiment provides that R⁸ is(C₁₋₃)alkyl. In a further embodiment, R⁸ is —C(O)NH₂. Non-limitingexemplary R² groups under these circumstances include those illustratedas follows:

In a further embodiment in accordance with Formula I or II, R² can be—S(O)₂N(R^(a))(R^(b)). One embodiment provides that one of R^(a) andR^(b) is H, and the other is heteroaryl, e.g., 5- or 6-memberedheteroaryl. One embodiment provides that one of R^(a) and R^(b) is H,and the other is 5-membered heteroaryl (e.g., 2,3,5-thiadiazolyl).Non-limiting exemplary heteroaryl, groups that can be used asR^(a)/R^(b) include, such as, thiadiazolyl, thienyl, benzo[b]thienyl,naphtho[2,3-b]thienyl, thianthrenyl, furyl, benzofuryl, pyranyl,isobenzofuranyl, benzooxazonyl, chromenyl, xanthenyl, 2H-pyrrolyl,pyrrolyl, imidazolyl, pyrazolyl, pyridyl, pyrazinyl, pyrimidinyl,pyridazinyl, isoindolyl, 3H-indolyl, indolyl, indazolyl, purinyl,isoquinolyl, quinolyl, phthalazinyl, naphthyridinyl, cinnolinyl,quinazolinyl, pteridinyl, 4aH-carbazolyl, carbazolyl, β-carbolinyl,phenanthridinyl, acridinyl, pyrimidinyl, phenanthrolinyl, phenazinyl,thiazolyl, isothiazolyl, phenothiazolyl, isoxazolyl, furazanyl, andphenoxazinyl. Further, any of the above-mentioned heteroaryl groups canbe further optionally substituted by one, two, or three same ordifferent heteroaryl substituent groups (as above defined).

In one embodiment, the Invention provides a compound of Formula III:

or a pharmaceutically acceptable salt, solvate, hydrate, N-oxide, ordiastereomer thereof, wherein R¹, R², and A groups are defined in theway set forth above.

In another embodiment, the Invention provides a compound of Formula IV:

or a pharmaceutically acceptable salt, solvate, hydrate, N-oxide, ordiastereomer thereof, wherein R¹, R², and A groups are defined in theway set forth above.

The Invention also provides a compound of Formula V:

or a pharmaceutically acceptable salt, solvate, hydrate, N-oxide, ordiastereomer thereof, wherein R¹, R², and A groups are defined in theway set forth above.

In a further embodiment, the Invention provides a compound of FormulaVI:

or a pharmaceutically acceptable salt, solvate, hydrate, N-oxide, ordiastereomer thereof, wherein R¹, R², and A groups are defined in theway set forth above.

In a separate embodiment in accordance with any one of Formulae I to VI,Λ is optionally-substituted heteroaryl, e.g., a 6-membered heteroarylgroup optionally substituted by one, two, three, four groups selectedfrom the group of the above-defined substituents to a heteroaryl group.Non-limiting exemplary heteroaryl groups that may be used as A include,such as, thiadiazolyl, thienyl, benzo[b]thienyl, thianthrenyl, furyl,benzofuryl, pyranyl, isobenzofuranyl, benzooxazonyl, xanthenyl,2H-pyrrolyl, pyrrolyl, imidazolyl, pyrazolyl, pyridyl, pyrazinyl,pyrimidinyl, pyridazinyl, isoindolyl, 3H-indolyl, indolyl, indazolyl,purinyl, isoquinolyl, quinolyl, phthalazinyl, naphthyridinyl,cinnolinyl, quinazolinyl, pteridinyl, 4aH-carbazolyl, carbazolyl,β-carbolinyl, phenanthridinyl, acridinyl, pyrimidinyl, phenanthrolinyl,phenazinyl, thiazolyl, isothiazolyl, phenothiazolyl, isoxazolyl,furazanyl, and phenoxazinyl.

In certain embodiments in accordance with any one of Formulae I to VI, Λis optionally-substituted pyridyl, optionally-substituted pyrimidyl, oroptionally-substituted triazinyl, wherein each of the pyridyl,pyrimidyl, or triazinyl groups can be further optionally substituted byone, two, or three same or different heteroaryl substituent groups (asabove defined).

A further embodiment in accordance with any one of Formulae I to VIprovides that A is a saturated or unsaturated optionally-substitutedcycloalkyl group. For example, A is cyclohexyl either unsubstituted orsubstituted with one, two, or three substituents independently selectedfrom the group consisting of the above-defined substituents for thecycloalkyl group. Another example provides that A is cyclohexenyl eitherunsubstituted or substituted with one, two, or three substituentsindependently selected from the group consisting of the above-definedsubstituents for the cycloalkyl group.

In one embodiment in accordance with any one of Formulae I to VI, A isoptionally-substituted phenyl, i.e., a phenyl group optionallysubstituted by one, two, three, four groups selected from the group ofthe above-defined substituents to an aryl group. In one embodiment, theInvention provides a compound of Formula VII or a pharmaceuticallyacceptable salt, solvate, hydrate, N-oxide, or diastereomer thereof:

Wherein

W¹, W², and W³, each independently, are CH or N, provided that at leastone of W¹, W² and W³ is N; and

R^(1a) is selected from the group consisting of H, (C₁₋₃)alkyl,halo(C₁₋₃)alkyl, halo(C₁₋₃)alkoxy, (C₁₋₃)alkoxy, halogen, amino,—C(O)NH₂, [(C₁₋₃)alkyl]amino, and hydroxyl.

Another embodiment of the Invention provides a compound of Formula VIIIor a pharmaceutically acceptable salt, solvate, hydrate, N-oxide, ordiastereomer thereof:

Wherein

W¹, W², and W³, each independently, are CH or N, provided that at leastone of W¹, W² and W³ is N; and

R^(1b) is selected from the group consisting of H(C₁₋₃)alkyl,halo(C₁₋₃)alkyl, halo(C₁₋₃) alkoxy, (C₁₋₃)alkoxy, halogen, amino,—C(O)NH₂, [(C₁₋₃)alkyl]amino, and hydroxyl.

In another embodiment, Compounds of the Invention include compoundspresented in TABLE 2.and the pharmaceutically acceptable salts,solvates, hydrates. N-oxides, and diasteromers thereof.

TABLE 2 Cpd No. Structure Chemical name 22

(S)-6-((1-amino-1-oxopropan- 2-yl)amino)-2-(5-(4-(trifluoromethyl)phenyl)-3,4- dihydroisoquinolin-2(1H)-yl)pyrimidine-4-carboxamide 23

(S)-6-((1-amino-1-oxopropan- 2-yl)amino)-2-(5-(5-(trifluoromethyl)pyridin-2-yl)- 3,4-dihydroisoquinolin-2(1H)-yl)pyrimidine-4-carboxamide 24

(S)-6-((1-amino-1-oxopropan- 2-yl)amino)-2-(5-(2-(trifluoromethyl)phenyl)-3,4- dihydroisoquinolin-2(1H)-yl)pyrimidine-4-carboxamide 25

6-(5-(4-(trifluoromethyl)- phenyl)-3,4-dihydro- isoquinolin-2(1H)-yl)-picolinamide 26

(2S,3R)-2,3-dihydroxy-3-(6-(5- (4-(trifluoromethyl)phenyl)-3,4-dihydroisoquinolin-2(1H)- yl)pyridin-2-yl)propanamide 27

(S)-6-((1-amino-1-oxopropan- 2-yl)amino)-2-(5-(3-(trifluoromethyl)phenyl)-3,4- dihydroisoquinolin-2(1H)-yl)pyrimidine-4-carboxamide 28

(S)-6-((1-amino-1-oxopropan- 2-yl)amino)-2-(5-(cyclohex-1-en-1-yl)-3,4-dihydro- isoquinolin-2(1H)- yl)pyrimidine-4-carboxamide 29

N-(1,2,4-thiadiazol-5-yl)-6-(5- (4-(trifluoromethyl)phenyl)-3,4-dihydroisoquinolin-2(1H)- yl)pyridine-2-sulfonamide 30

6-chloro-4-(5-(4- (trifluoromethyl)phenyl)-3,4-dihydroisoquinolin-2(1H)- yl)picolinonitrile 31

(S)-6-((1-amino-1-oxopropan- 2-yl)amino)-2-(5-cyclohexyl-3,4-dihydroisoquinolin-2(1H)- yl)pyrimidine-4-carboxamide 35

(S)-6-(1,2-dihydroxyethyl)-4- (5-(4-(trifluoromethyl)phenyl)-3,4-dihydroisoquinolin-2(1H)- yl)picolinamide 36

(R)-6-(1,2-dihydroxyethyl)-4- (5-(4-(trifluoromethyl)phenyl)-3,4-dihydroisoquinolin-2(1H)- yl)picolinamide

The Invention also provides compounds useful as synthetic intermediatesin the preparation of blockers of one or more sodium (Na⁺) channels.

The Invention encompasses any of the Compounds of the Invention beingisotopically-labelled (i.e., radiolabeled) by having one or more atomsreplaced by an atom having a different atomic mass or mass number.Examples of isotopes that can be incorporated into the disclosedcompounds include isotopes of hydrogen, carbon, nitrogen, oxygen,phosphorous, fluorine and chlorine, such as ²H, ³H, ¹¹C, ¹³C, ¹⁴C, ¹⁵N,¹⁸O, ¹⁷O, ³¹P, ³²P, ³⁵S, ¹⁸F, and ³⁶Cl, respectively, e.g., ³H, ¹¹C, and¹⁴C. Isotopically-labeled Compounds of the Invention can be prepared bymethods known in the art.

The Invention further encompasses ³H. ¹¹C, or ¹⁴C radiolabeled Compoundsof the Invention and the use of any such compounds as radioligands fortheir ability to bind to the sodium channel. For example, one use of thelabeled compounds of the Invention is the characterization of specificreceptor binding. Another use of a labeled Compound of the Invention isan alternative to animal testing for the evaluation ofstructure-activity relationships. For example, the receptor assay can beperformed at a fixed concentration of a labeled Compound of theInvention and at increasing concentrations of a test compound in acompetition assay. For example, a tritiated Compound of the Inventioncan be prepared by introducing tritium into the particular compound, forexample, by catalytic dehalogenation with tritium. This method mayinclude reacting a suitably halogen-substituted precursor of thecompound with tritium gas in the presence of a suitable catalyst, forexample, Pd/C, in the presence or absence of a base. Other suitablemethods for preparing tritiated compounds can be found in Filer,Isotopes in the Physical and Biomedical Sciences, Vol. 1, LabeledCompounds (Part A), Chapter 6 (1987). ¹⁴C-labeled compounds can beprepared by employing starting materials having a ¹⁴C carbon.

Some of the Compounds of the Invention may contain one or moreasymmetric centers and may thus give rise to enantiomers, diastereomers,and other stereoisomeric forms. The Invention is meant to encompass theuse of all such possible forms, as well as their racemic and resolvedforms and mixtures thereof. The individual enantiomers can be separatedaccording to methods known in the art in view of the Invention. When thecompounds described herein contain olefinic double bonds or othercenters of geometric asymmetry, and unless specified otherwise, it isintended that they include both E and Z geometric isomers. All tautomersare intended to be encompassed by the Invention as well.

The Invention encompasses the preparation and use of salts of theCompounds of the Invention, including non-toxic pharmaceuticallyacceptable salts. Examples of pharmaceutically acceptable addition saltsinclude inorganic and organic acid addition salts and basic salts. Thepharmaceutically acceptable salts include, but are not limited to, metalsalts such as sodium salt, potassium salt, cesium salt and the like;alkaline earth metals such as calcium salt, magnesium salt and the like;organic amine salts such as triethylamine salt, pyridine salt, picolinesalt, ethanolamine salt, triethanolamine salt, dicyclohexylamine salt,N,N′-dibenzylethylenediamine salt and the like: inorganic acid saltssuch as hydrochloride, hydrobromide, phosphate, sulphate and the like;organic acid salts such as citrate, lactate, tartrate, maleate,fumarate, mandelate, acetate, dichloroacetate, trifluoroacetate,oxalate, formate and the like; sulfonates such as methanesulfonate,benzenesulfonate, p-toluenesulfonate and the like; and amino acid saltssuch as arginate, asparginate, glutamate and the like.

Acid addition salts can be formed by mixing a solution of the particularCompound of the Invention with a solution of a pharmaceuticallyacceptable non-toxic acid such as hydrochloric acid, fumaric acid,maleic acid, succinic acid, acetic acid, citric acid, tartaric acid,carbonic acid, phosphoric acid, oxalic acid, dichloroacetic acid, or thelike. Basic salts can be formed by mixing a solution of the Compound ofthe Invention with a solution of a pharmaceutically acceptable non-toxicbase such as sodium hydroxide, potassium hydroxide, choline hydroxide,sodium carbonate and the like.

The Invention also encompasses the preparation and use of solvates ofCompounds of the Invention. Solvates typically do not significantlyalter the physiological activity or toxicity of the compounds, and assuch may function as pharmacological equivalents. The term “solvate” asused herein is a combination, physical association and/or solvation of aCompound of the Invention with a solvent molecule such as, e.g. adisolvate, monosolvate or hemisolvate, where the ratio of solventmolecule to Compound of the Invention is about 2:1, about 1:1 or about1:2, respectively. This physical association involves varying degrees ofionic and covalent bonding, including hydrogen bonding. In certaininstances, the solvate can be isolated, such as when one or more solventmolecules are incorporated into the crystal lattice of a crystallinesolid. Thus, “solvate” encompasses both solution-phase and isolatablesolvates. Compounds of the Invention can be present as solvated formswith a pharmaceutically acceptable solvent, such as water, methanol,ethanol, and the like, and it is intended that the disclosure includesboth solvated and unsolvated forms of Compounds of the Invention. Onetype of solvate is a hydrate. A “hydrate” relates to a particularsubgroup of solvates where the solvent molecule is water. Solvatestypically can function as pharmacological equivalents. Preparation ofsolvates is known in the art. See, for example, M. Caira et al, J.Pharmaceut. Sci., 93(3):601-611 (2004), which describes the preparationof solvates of fluconazole with ethyl acetate and with water. Similarpreparation of solvates, hemisolvates, hydrates, and the like aredescribed by E. C, van Tonder et al., AAPS Pharm. Sci. Tech.,5(1):Article 12 (2004), and A. L. Bingham et al., Chem. Commun. 603-604(2001). A typical, non-limiting, process of preparing a solvate wouldinvolve dissolving a Compound of the Invention in a desired solvent(organic, water, or a mixture thereof) at temperatures above 20° C. toabout 25° C., then cooling the solution at a rate sufficient to formcrystals, and isolating the crystals by known methods, e.g., filtration.Analytical techniques such as infrared spectroscopy can be used toconfirm the presence of the solvent in a crystal of the solvate.

Further, the Invention encompasses hydrates of any of the disclosedcompounds. It is appreciated that a hydrate may be considered as aspecific type of solvate. In other words, it may be appreciated in theart that a “hydrate” is a particular subgroup of solvates where thesolvent molecule is water.

The Invention is also meant to encompass prodrugs of any of thedisclosed compounds. As used herein, prodrugs are considered to becompounds with moieties that can be metabolized in vivo. In general,such prodrugs will be functional derivatives of compounds of any of theformulae delineated herein, which will be readily convertible in vivo,e.g., by being metabolized, into the required compound of any of theformulae. Conventional procedures for the selection and preparation ofsuitable prodrug derivatives are described in, for example, Design ofProdrugs, H. Bundgaard ed., Elsevier (1985): “Drug and Enzyme Targeting,Part A,” K. Widder et al. eds., Vol. 112 in Methods in Enzymology,Academic Press (1985); Bundgaard, “Design and Application of Prodrugs,”Chapter 5 (pp. 113-191) in A Textbook of Drug Design and Development, P.Krogsgaard-Larsen and H. Bundgaard eds., Harwood Academic Publishers(1991); Bundgaard et al., Adv. Drug Delivery Revs. 8:1-38 (1992);Bundgaard et al., J. Pharmaceut. Sci. 77:285 (1988); and Kakeya et al.,Chem. Pharm. Bull. 32:692 (1984).

Examples of prodrugs and their use are well known in the art (e.g.,Berge et al. (1997) “Pharmaceutical Salts”, J. Pharm. Sci. 66:1-19).Non-limiting examples of prodrugs include esters or amides of Compoundsof the Invention having carboxy, hydroxy or amino groups as asubstituent, and these can be prepared by reacting such parent compoundswith anhydrides such as succinic anhydride.

Methods and Use of the Compounds of the Invention

In certain embodiments, the Compounds of the Invention are useful fortreating pain. Without wishing to be bound by any theory, it is believedthat certain Compounds of the Invention can act as blockers of one ormore sodium (Na⁺) channels. Therefore, a number of diseases andconditions mediated by sodium ion influx can be treated by employingthese compounds. The Invention is further directed generally to a methodfor treating a disorder responsive to blockade of sodium channels in ananimal suffering from, or at risk of suffering from, said disorder, saidmethod comprising administering to the animal an effective amount of oneor more Compounds of the Invention.

The invention is further directed to a method of modulating sodiumchannels in an animal in need thereof, said method comprisingadministering to the animal a modulating-effective amount of at leastone Compound of the Invention.

More specifically, the invention provides a method of treating stroke,neuronal damage resulting from head trauma, epilepsy, neuronal lossfollowing global and focal ischemia, pain (e.g., acute pain, chronicpain, which includes but is not limited to neuropathic pain,postoperative pain, and inflammatory pain, or surgical pain), aneurodegenerative disorder (e.g., Alzheimer's disease, amyotrophiclateral sclerosis (ALS), or Parkinson's disease), migraine, manicdepression, tinnitus, myotonia, a movement disorder, or cardiacarrhythmia, or providing local anesthesia. In one embodiment, theInvention provides a method of treating pain. In another embodiment, thetype of pain is chronic pain. In another embodiment, the type of pain isneuropathic pain. In another embodiment, the type of pain ispostoperative pain. In another embodiment, the type of pain isinflammatory pain. In another embodiment, the type of pain is surgicalpain. In another embodiment, the type of pain is acute pain. In anotherembodiment, the treatment of pain (e.g., chronic pain, such asneuropathic pain, postoperative pain, or inflammatory pain, acute painor surgical pain) is preemptive. In another embodiment, the treatment ofpain is palliative. In each instance, such method of treatment requiresadministering to an animal in need of such treatment an amount of aCompound of the Invention that is therapeutically effective in achievingsaid treatment. In one embodiment, the amount of such compound is theamount that is effective to block sodium channels in vitro. In oneembodiment, the amount of such compound is the amount that is effectiveto block sodium channels in vivo.

Chronic pain includes, but is not limited to, inflammatory pain,postoperative pain, cancer pain, osteoarthritis pain associated withmetastatic cancer, trigeminal neuralgia, acute herpetic and postherpeticneuralgia, diabetic neuropathy, causalgia, brachial plexus avulsion,occipital neuralgia, reflex sympathetic dystrophy, fibromyalgia, gout,phantom limb pain, burn pain, and other forms of neuralgia, neuropathic,and idiopathic pain syndromes.

Chronic somatic pain generally results from inflammatory responses totissue injury such as nerve entrapment, surgical procedures, cancer orarthritis (Brower, Nature Biotechnology 18:387-391 (2(0))).

The inflammatory process is a complex series of biochemical and cellularevents activated in response to tissue injury or the presence of foreignsubstances (Levine, Inflammatory Pain, In: Textbook of Pain, Wall andMelzack eds., 3^(rd) ed., 1994). Inflammation often occurs at the siteof injured tissue, or foreign material, and contributes to the processof tissue repair and healing. The cardinal signs of inflammation includeerythema (redncss), heat, edema (swelling), pain and loss of function(ibid.). The majority of patients with inflammatory pain do notexperience pain continually, but rather experience enhanced pain whenthe inflamed site is moved or touched. Inflammatory pain includes, butis not limited to, that associated with osteoarnhritis and rheumatoidarthritis.

Chronic neuropathic pain is a heterogeneous disease state with anunclear etiology. In chronic neuropathic pain, the pain can be mediatedby multiple mechanisms. This type of pain generally arises from injuryto the peripheral or central nervous tissue. The syndromes include painassociated with spinal cord injury, multiple sclerosis, post-herpeticneuralgia, trigeminal neuralgia, phantom pain, causalgia, and reflexsympathetic dystrophy and lower back pain. Chronic pain is differentfrom acute pain in that patients suffer the abnormal pain sensationsthat can be described as spontaneous pain, continuous superficialburning and/or deep aching pain. The pain can be evoked by heat-, cold-,and mechano-hyperalgesia or by heat-, cold-, or mechano-allodynia.

Neuropathic pain can be caused by injury or infection of peripheralsensory nerves. It includes, but is not limited to, pain from peripheralnerve trauma, herpes virus infection, diabetes mellitus, causalgia,plexus avulsion, neuroma, limb amputation, and vasculitis. Neuropathicpain is also caused by nerve damage from chronic alcoholism, humanimmunodeficiency virus infection, hypothyroidism, uremia, or vitamindeficiencies. Stroke (spinal or brain) and spinal cord injury can alsoinduce neuropathic pain. Cancer-related neuropathic pain results fromtumor growth compression of adjacent nerves, brain, or spinal cord. Inaddition, cancer treatments, including chemotherapy and radiationtherapy, can also cause nerve injury. Neuropathic pain includes but isnot limited to pain caused by nerve injury such as, for example, thepain from which diabetics suffer.

The Invention is also directed to the use of a Compound of the Inventionin the manufacture of a medicament for treating pain. Further, theInvention is directed to the use of a Compound of the Invention in themanufacture of a medicament for treating a disorder responsive toblockade of sodium channels (e.g., any of the disorders listed above) inan animal suffering from said disorder.

General Synthesis of Compounds

The Compounds of the Invention (e.g., those of Formula I) can be madeusing conventional organic synthesis in view of this disclosure, or bythe illustrative methods shown in the Scheme below.

Compound A, where BR′R″ is a boronic acid or ester, is converted toCompound C by reaction with Compound B in the presence of a suitablecatalyst (such as, Pd(PPh₃)₂Cl₂) and a suitable base (such as, Cs₂CO₃)in a suitable solvent (such as, a DME/aq. EtOH mixture). Compound C,where PG is a protecting group, is converted to Compound D byappropriate deprotection techniques known to one skilled in the an (e.g.Wuts, P. G. M.; Greene. T. W. “Greene's Protective Groups in OrganicSynthesis”, 4th Ed., J. Wiley & Sons, N Y, 2007). Compound D isconverted to Compound F by reaction with Compound E in the presence of asuitable base (such as, Cs₂CO₃) in a suitable solvent (such as, DMF).

Subsequent side chain modifications can be accomplished via appropriatefunctional group manipulations known to one skilled in the art.

Testing of Compounds

Certain compounds of the Invention were assessed by sodium mobilizationand/or electrophysiological (EP) assays for sodium channel blockeractivity. One aspect of the invention is based on the use of theCompounds of the Invention as sodium channel blockers. Based upon thisproperty, Compounds of the Invention are considered useful in treating acondition or disorder responsive to the blockade of sodium ion channels.e.g., stroke, neuronal damage resulting from head trauma, epilepsy,seizures, general epilepsy with febrile seizures, severe myoclonicepilepsy in infancy, neuronal loss following global and focal ischemia,migraine, familial primary erythromelalgia, paroxysmal extreme paindisorder, cerebellar atrophy, ataxia, dystonia, tremor, mentalretardation, autism, a neurodegenerative disorder (e.g., Alzheimer'sdisease, amyotrophic lateral sclerosis (ALS), or Parkinson's disease),manic depression, tinnitus, myotonia, a movement disorder, cardiacarrhythmia, or providing local anesthesia. Compounds of the Inventionare also expected to be effective in treating pain. e.g., acute pain,chronic pain, which includes but is not limited to, neuropathic pain,postoperative pain, and inflammatory pain, or surgical pain.

Certain embodiments of the Invention provide compounds described supra,useful as blockers of sodium channels. Without wishing to be found byany theory, certain compounds of the Invention having useful sodiumchannel blocking properties exhibit an IC₅₀ for Na_(v)1.1, Na_(v)1.2,Na_(v)1.3, Na_(v)1.4, Na_(v)1.5, Na_(v)1.6, Na_(v)1.7, Na_(v)1.8, and/orNa_(v)1.9 of about 100 μM or less, e.g., about 50 μM or less, about 25μM or less, about 10 μM or less, about 5 μM or less, or about 1 μM orless, in sodium mobilization and/or electrophysiological assays. Incertain embodiments, Compounds of the Invention exhibit an IC₅₀ forNa_(v)1.7 of 100 μM or less, about 50 μM or less, about 25 μM or less,about 10 μM or less, about 5 μM or less, about 1 μM or less, about 0.5μM or less, about 0.1 μM or less, about 0.05 μM or less, or about 0.01μM or less. Compounds of the Invention can be tested for their Na⁺channel blocking activity using methods known in the art and by thefollowing fluorescence imaging and electrophysiological in vitro assaysand/or in vivo assays.

In one embodiment, Compounds of the Invention demonstrate substantiallyno penetration across the CNS blood-brain barrier in a mammal. Suchcompounds are referred to as “peripherally restricted” as a means todesignate their PNS versus CNS tissue selectivity.

In one embodiment, the PNS:CNS concentration ratio of a peripherallyrestricted Compound of the Invention is about 5:1, about 10:1, about20:1, about 30:1; about 50:1; about 100:1, about 250:1, about 500:1,about 1000:1, about 5,000:1, about 10,000:1, or more. Compounds of theInvention can be tested for their ability to penetrate the centralnervous system using in vitro and in vivo methods known in the art.

In Vitro Assay Protocols FLIPR® Assays

Recombinant Na_(v)1.7 Cell Line: In vitro assays were performed in arecombinant cell line expressing cDNA encoding the alpha subunit(Na_(v)1.7, SCN9a. PN1, NE) of human Na_(v)1.7 (Accession No.NM_002977). The cell line was provided by investigators at YaleUniversity (Cumnins et al, J. Neurosci. 18(23): 9607-9619 (1998)). Fordominant selection of the Na_(v)1.7-expressing clones, the expressionplasmid co-expressed the neomycin resistance gene. The cell line wasconstructed in the human embryonic kidney cell line. HEK293, under theinfluence of the CMV major late promoter, and stable clones wereselected using limiting dilution cloning and antibiotic selection usingthe neomycin analogue, G418. Recombinant beta and gamma subunits werenot introduced into this cell line. Additional cell lines expressingrecombinant Na_(v)1.7 cloned from other species can also be used, aloneor in combination with various beta subunits, gamma subunits orchaperones.

Non-recombinant Cell Lines Expressing Native Na_(v)1.7: Alternatively,in vitro assays can be performed in a cell line expressing native,non-recombinant Na_(v)1.7, such as the ND7 mouse neuroblastoma X ratdorsal root ganglion (DRG) hybrid cell line ND7/23, available from theEuropean Cell Culture Collection (Cat. No. 92090903, Salisbury,Wiltshire, United Kingdom). The assays can also be performed in othercell lines expressing native, non-recombinant Na_(v)1.7, from variousspecies, or in cultures of fresh or preserved sensory neurons, such asdorsal root ganglion (DRG) cells, isolated from various species. Primaryscreens or counter-screens of other voltage-gated sodium channels canalso be performed, and the cell lines can be constructed using methodsknown in the art, purchased from collaborators or commercialestablishments, and they can express either recombinant or nativechannels. The primary counter-screen is for one of the central neuronalsodium channels, Na_(v)1.2 (rBIIa), expressed in HEK293 host cells(Ilyin et al., Br. J. Pharmacol. 144:801-812 (2005)). Pharmacologicalprofiling for these counter-screens is carried out under conditionssimilar to the primary or alternative Na_(v)1.7 assays described below.

Cell maintenance: Unless otherwise noted, cell culture reagents werepurchased from Mediatech of Herndon, Va. The recombinantNa_(v)1.7/HEK293 cells were routinely cultured in growth mediumconsisting of Dulbecco's minimum essential medium containing 10% fetalbovine serum (3S, Hyclone, Thermo Fisher Scientific, Logan. T), 100U/ml, penicillin, 100 μg/mL streptomycin, 2-4 mM L-glutamine, and 500mg/m. G418. For natural, non-recombinant cell lines, the selectiveantibiotic was omitted, and additional media formulations can be appliedas needed.

Assay Buffer: The assay buffer was formulated by removing 120 mL from a1 L bottle of fresh, sterile dH₂O (Mediatech, Herndon, Va.) and adding100 mL of 10×HBSS that does not contain Ca⁺⁺ or Mg⁺⁺ (Gibco, Invitrogen,Grand Island, N.Y.) followed by 20 mL of 1.0 M Hepes, pH 7.3 (FisherScientific, BP299-100). The final buffer consisted of 20 mM Hepes, pH7.3, 1.261 mM CaCl₂, 0.493 mM MgCl₂, 0.407 mM Mg(SO)₄. 5.33 mM KC, 0.441mM KH₂PO₄. 137 mM NaCl, 0.336 mM Na₂HPO₄ and 0.556 mM D-glucose (Hankset al., Proc. Soc. Exp. Biol. Med. 71:196 (1949)), and the simpleformulation was typically the basic buffer throughout the assay (i.e.,all wash and addition steps).

CoroNa™ Green AM Na⁺ Dye for Primary Fluorescence Assay: Thefluorescence indicator used in the primary fluorescence assay was thecell permeant version of CoroNa™ Green (Invitrogen, Molecular Probes,Eugene, Oreg.), a dye that emits light in the fluorescence range(IIarootunian et al., J. Biol. Chem. 264(32):19458-19467 (1989)). Theintensity of this emission, but not the wavelength range, is increasedwhen the dye is exposed to Na⁺ ions, which it can bind with partialselectivity. Cells expressing Na_(v)1.7 or other sodium channels wereloaded with the CoroNa™ Green dye immediately in advance of thefluorescence assay, and then, after agonist stimulation, themobilization of Na⁺ ions was detected as the Na⁺ ions flowed from theextracellular fluid into the cytoplasm through the activated sodiumchannel pores. The dye was stored in the dark as a lyophilized powder,and then an aliquot was dissolved immediately before the cell loadingprocedure, according to the instructions of the manufacturer, to a stockconcentration of 10 mM in DMSO. It was then diluted in the assay bufferto a 4× concentrated working solution, so that the final concentrationof dye in the cell loading buffer was 5 μM.

Membrane Potential Dye for Alternative Fluorescence Assays: Afluorescence indicator that can be used in alternative fluorescenceassays is the blue version membrane potential dye (MDS, MolecularDevices, Sunnyvale, Calif.), a dye that detects changes in moleculesfollowing a change in membrane potential. An increase in fluorescence isexpected if agonist stimulation provokes a change in membrane potential.Cells expressing Na_(v)1.7 or other sodium channels are incubated withthe membrane potential dye 30-60 minutes before the fluorescence assay.In the case of the KCl pre-stimulation version of the assay, the dye andall other components are washed out immediately before the assay, andthe dye is then replaced. In the version lacking KCl pre-stimulation,the dye remains on the cells and is not washed out or replaced. The dyeis stored in the dark as a lyophilized powder, and then an aliquotdissolved in assay buffer to form a 20×-concentrated stock solution thatcan be used for several weeks. Agonists: In the fluorescence assays, twoagonists were used in combination, namely 1) veratridine; and 2) thevenom from the yellow scorpion, Leiurus quinquestriatus hebraeus.Veratridine is an alkaloid small molecule that facilitates the captureof channel openings by inhibiting inactivation, and the scorpion venomis a natural preparation that includes peptide toxins selective fordifferent subsets of voltage-gated sodium channels. These scorpiontoxins inhibit the fast inactivation of their cognate target channels.Stock solutions of the agonists were prepared to 40 mM in DMSO(veratridine) and 1 mg/mL in dH₂O (scorpion venom), and then diluted tomake a 4× or 2× stock (depending on the particular assay) in assaybuffer, the final concentration being 100 μM (veratridine) and 10 μg/mL(scorpion venom). Both of the agonists were purchased from SigmaAldrich, St. Louis, Mo.

Test Compounds: Test compounds were dissolved in DMSO to yield 10 mMstock solutions. The stock solutions were further diluted using DMSO in1:3 serial dilution steps with 10 points (1000 μM, 3.333 μM, 1.111 μM,370 μM, 123 μM, 41 μM, 14 μM, 4.6 μM, 1.5 μM and 0.5 μM). The stocksolutions were further diluted in assay buffer (1:125) as 4× stockserial dilutions with a DMSO concentration of 0.8% (final [DMSO], in theassay, from the compounds component=0.2%), so that the compounds' finalconcentrations in the assay were 20 μM, 6.7 μM, 2.2 μM, 0.74 μM, 0.25 μMand 0.08 μM, 0.03 μM, 0.01 μM, 0.003 μM and 0.001 μM. If a particulartest article appeared to be especially potent, then the concentrationcurve was adjusted, e.g., to 10-fold lower concentrations, in order toperform the dose-response in a more relevant concentration range.Compound dilutions were added during the dye-loading and pre-stimulationstep, and then again during the fluorescence assay, early in the kineticread. Compound dilutions were added in duplicate rows across the middle80 wells of the %-well plate, whereas the fully stimulated and the fullyinhibited controls (positive and negative) were located in the top 4side wells and the bottom 4 side wells, respectively, on the left andright sides of the assay plate.

Data Analysis: The data were analyzed according to methods known tothose skilled in the art or using the GraphPad® Prism Program, version4.0 or higher (available from GraphPad Software. San Diego, Calif.) todetermine the IC₅₀ value for the test article. At least one standardreference compound was evaluated during each experiment.

FLIPR® or FLIPR^(TETRA)® sodium dye assay with KCl and test articlepre-incubation: Cells were prepared by plating the recombinant HEK293cells or other host cells expressing either recombinant ornon-recombinant, native. Na_(V)1.7 alpha subunit, alone or incombination with various beta and gamma subunits at a density of ˜40,000cells/well into a 96-well black, clear-bottom, PDL-coated plate. Theassay can be adapted to 384-well or 1,536-well format, if desired, usingproportionately fewer cells and less media. The plate was then incubatedin growth media, with or without selective antibiotic, overnight at 37°C. at 5% CO₂, 95% humidity, in preparation for the assay. Forcounter-screens of other voltage-gated sodium channels, the procedurewas very similar, though optimal densities of cells, media andsubsequent assay components can be fine-tuned for the particular cellline or isoform.

The next day, at the start of the assay, the media was flicked from thecells and the wells were washed once with 50 μl/well assay buffer (1×Hank's balanced salt solution without sodium bicarbonate or phenol red,20 mM Hepes, pH 7.3) and then pre-incubated with the test articles,CoroNar™ Green AM sodium dye (for cell loading) and KCl forre-polarization and synchronization of the channels in the entirepopulation of cells. For this dye-loading and pre-stimulation step, thecomponents were added as follows, immediately after the wash step: 1)first, the compound dilutions and controls were added as 4× concentratesin assay buffer at 50 μL/well: 2) CoroNa™ Green AM dye was diluted fromthe stock solution to 20 μM in assay buffer (4× concentrate) and addedto the plate at 50 μL/well: and 3) finally, a solution of 180 mM KCl(2×) was prepared by diluting a 2M stock solution into assay buffer andthe solution was added to the cells at 100 μl/well. The cells wereincubated at 25° C. in the dark for 30 min. before their fluorescencewas measured.

The plates containing dye-loaded cells were then flicked to remove thepre-incubation components and washed once with 100 μL/well assay buffer.A 100 μl/well aliquot of assay buffer was added back to the plate, andthe real-time assay was commenced. The fluorescence of cells wasmeasured using a fluorescence plate reader (FLIPR^(TETRA)® or FLIPR384®.MDS, Molecular Devices, Sunnyvale, Calif.) Samples were excited byeither a laser or a PMT light source (Excitation wavelength=470-495 mM)and the emissions are filtered (Emission wavelength=515-575 mM). Theadditions of compound and the channel activators in this cell-based,medium-to-high throughput assay were performed on the fluorescence platereader and the results (expressed as relative fluorescence units) werecaptured by means of camera shots every 1-3 sec., then displayed inreal-time and stored. Generally, there was a 15 sec. base line, withcamera shots taken every 1.5 sec., then the test compounds were added,then another 120 sec. baseline was conducted, with camera shots takenevery 3 sec.; and finally, the agonist solution (containing veratridineand scorpion venom) was added. The amplitude of fluorescence increase,resulting from the binding of Na⁺ ions to the CoroNa™ Green dye, wascaptured for ˜180 sec. thereafter. Results were expressed in relativefluorescence units (RFU) and can be determined by using the maximumsignal during the latter part of the stimulation; or the maximum minusthe minimum during the whole agonist stimulation period; or by takingthe area under the curve for the whole stimulation period.

The assay can be performed as a screening assay as well with the testarticles present in standard amounts (e.g., 10 μM) in only one or twowells of a multi-well plate during the primary screen. Hits in thisscreen were typically profiled more exhaustively (multiple times),subjected to dose-response or competition assays and tested in counterscreens against other voltage-gated sodium channels or otherbiologically relevant target molecules.

FLIPR® or FLIPR^(TETR)® membrane potential assay with KCl and testarticle pre-incubation: Cells are prepared by plating the recombinantHEK293 cells or other host cells expressing either recombinant ornon-recombinant, native, Na_(v)1.7 alpha subunit, alone or incombination with various beta and gamma subunits at a density of ˜40,000cells/well into a 96-well black, clear-bottom, PDL-coated plate. Theassay can be adapted to 384-well or 1.536-well format, if desired, usingproportionately less cells and media. The plate is then incubated ingrowth media, with or without selective antibiotic, overnight at 37° C.at 5% CO₂, 95% humidity, in preparation for the assay (see, e.g.,Benjamin et. al., J. Biomol. Screen 10(4):365-373 (2005)). For screensand counter-screens of other voltage-gated sodium channels, the assayprotocol is similar, though optimal densities of cells, media andsubsequent assay components can be fine-tuned for the particular cellline or sodium channel isoform being tested.

The next day, at the start of the assay, the media is flicked from thecells and the wells are washed once with 50 μL/well assay buffer (IXHank's balanced salt solution without sodium bicarbonate or phenol red,20 mM Hepes, pH 7.3) and then pre-incubated with the test articles, themembrane potential dye (for cell loading), and the KCl forre-polarization and synchronization of the channels in the entirepopulation of cells. For this dye-loading and pre-stimulation step, thecomponents are added as follows, immediately after the wash step: 1)first, the compound dilutions and controls are added as 4× concentratesin assay buffer at 50 μL/well; 2) membrane potential dye is diluted fromthe stock solution in assay buffer (4× concentrate) and added to theplate at 50 μL/well: and 3) finally, a solution of 180 mM KCl (2×) isprepared by diluting a 2M stock solution into assay buffer and thesolution added to the cells at 100 μL/well. The cells are incubated at37° C. in the dark for 30-60 min. before their fluorescence is measured.

The plates containing dye-loaded cells are then flicked to remove thepre-incubation components and washed once with 50 μL/well assay buffer.A 50 μL/well aliquot of membrane potential dye is added back to theplate, and the real-time assay is commenced. The fluorescence of cellsis measured using a fluorescence plate reader (FLIPR^(TETRA)® orFLIPR384®, MDS, Molecular Devices, Sunnyvale, Calif.). Samples areexcited by either a laser or a PMT light source (Excitationwavelength=510-545 mM) and the emissions are filtered (Emissionwavelength=565-625 mM). The additions of the compounds (first) and thenthe channel activators (later) in this are performed on the fluorescenceplate reader and the results, expressed as relative fluorescence units(RFU), are captured by means of camera shots every 1-3 sec., thendisplayed in real-time and stored. Generally, there is a 15 sec. baseline, with camera shots taken every 1.5 sec., then the test compoundsare added, then another 120 sec. baseline is conducted, with camerashots taken every 3 sec.; and finally, the agonist solution (containingveratridine and scorpion venom) is added. The amplitude of fluorescenceincrease, resulting from the detection of membrane potential change, iscaptured for ˜120 sec. thereafter. Results are expressed in relativefluorescence units (RFU) and can be determined by using the maximumsignal during the latter part of the stimulation; or the maximum minusthe minimum during the whole stimulation period: or by taking the areaunder the curve for the whole stimulation period.

The assay can be performed as a screening assay as well with the testarticles present in standard amounts (e.g., 10 μM) in only one or twowells of a multi-well plate during the primary screen. Hits in thisscreen are typically profiled more exhaustively (multiple times),subjected to dose-response or competition assays and tested in counterscreens against other voltage-gate sodium channels or other biologicallyrelevant target molecules.

FLIPR® or FLIPR^(TETRA)® sodium dye assay without KCl and test articlepre-incubation: Cells are prepared by plating the recombinant HEK293cells or other host cells expressing either recombinant ornon-recombinant, native, Na_(V)1.7 alpha subunit, alone or incombination with various beta and gamma subunits at a density of ˜40,000cells/well into a 96-well black, clear-bottom, PDL-coated plate. Theassay can be adapted to 384-well or 1,536-well format, if desired, usingproportionately less cells and media. The plate is then incubated ingrowth media, with or without selective antibiotic, overnight at 37° C.at 5% CO₂, 95% humidity, in preparation for the assay. Forcounter-screens of other voltage-gated sodium channels, the procedure isvery similar, though optimal densities of cells, media and subsequentassay components can be fine-tuned for the particular cell line orisoform.

The next day, at the start of the assay, the media is flicked from thecells and the wells washed once with 50 μL/well assay buffer (X Hank'sbalanced salt solution without sodium bicarbonate or phenol red, 20 mMHepes, pH 7.3). Membrane potential dye is then added to each well of the96-well plate (50 μL/well), from a freshly diluted sample of the stock(now at 4× concentration) in the assay buffer. The cells are incubatedat 37° C. in the dark for 30-60 min. before their fluorescence ismeasured.

In this standard membrane potential assay, the 96-well plate containingdye-loaded cells is then loaded directly onto the plate reader withoutaspirating the dye solution and without any further washing of thecells. The fluorescence of cells is measured using a fluorescence platereader (FLIPR^(TETRA)® or FLIPR384®, MDS. Molecular Devices, Sunnyvale,Calif.). Samples are excited by either a laser or a PMT light source(Excitation wavelength=510-545 mM) and the emissions are filtered(Emission wavelength=565-625 nM). The additions of the compounds (first,50 μL/well from a 4× stock plate) and then the channel activators(later, 100 μL/well from a 2× stock solution) in this kinetic assay areperformed on the fluorescence plate reader and the results, expressed asrelative fluorescence units (RFU), are captured by means of camera shotsevery 1-3 sec., then displayed in real-time and stored. Generally, thereis a 15 sec. base line, with camera shots taken every 1.5 sec., then thetest compounds are added, then another 120 sec. baseline is conducted,with camera shots taken every 3 sec.; and finally, the agonist solution(containing veratridine and scorpion venom) is added. The amplitude offluorescence increase, resulting from the detection of membranepotential change, is captured for ˜120 sec. thereafter. Results areexpressed in relative fluorescence units (RFU) and can be determined byusing the maximum signal during the latter part of the stimulation; orthe maximum minus the minimum during the whole stimulation period; or bytaking the area under the curve for the whole stimulation period.

The assay can be performed as a screening assay as well, with the testarticles present in standard amounts (e.g. 10 μM) in only one or twowells of a multi-well plate during the primary screen. Hits in thisscreen are typically profiled more exhaustively (multiple times),subjected to dose-response or competition assays and tested in counterscreens against other voltage-gate sodium channels or other biologicallyrelevant target molecules.

Electrophysiology Assay

Cells Manual Electrophysiology: The hNa_(v)1.7 expressing HEK-293 cellsare plated on 35 mm culture dishes pre-coated with poly-D-lysine instandard DMEM culture media (Mediatech, Inc., Herndon, Va.) andincubated in a 5% CO₂ incubator at 37° C. Cultured cells are usedapproximately 12-48 hours after plating.

Cells Automated Electrophysiology: The hNa_(v)1.7 expressing HEK-293cells are plated on tissue culture flasks in standard DMEM culture media(Mediatech, Inc.) and incubated in a 5% CO₂ incubator at 37°. Culturedcells are used approximately 12-48 hours after plating.

Manual Electrophysiology: On the day of experimentation, the 35 mm dishis placed on the stage of an inverted microscope equipped with aperfusion system that continuously perfuses the culture dish with freshrecording media. A gravity driven superfusion system is used to applytest solutions directly to the cell under evaluation. This “shooter”system consists of an array of glass pipettes connected to a motorizedhorizontal translator. The outlet of the shooter is positionedapproximately 100 μm from the cell of interest.

Whole cell currents are recorded using the whole-cell patch clampconfiguration using an Axopatch 200B amplifier (Axon Instruments, FosterCity Calif.), 1322A A/D converter (Axon Instruments) and pClamp software(v. 8; Axon Instruments) and stored on a personal computer. Gigaseals amformed and the whole-cell configuration is established in voltage clampmode, and membrane currents generated by hNa_(v)1.7 channels arerecorded. Borosilicate glass pipettes with resistance values between 1.5and 2.0 MΩ when filled with pipette solution are used and seriesresistance (<5 MΩ) is compensated by 75-80%. Signals are sampled at 50kHz and low pass filtered at 3 kHz.

Automated Electrophysiology: On the day of experimentation, cells areprepared by removing media and digesting with appropriate enzymes tosuspend cells in external solution.

Whole cell currents are recorded using the whole-cell patch clampconfiguration using an Patchliner (Nanion Technologies, Munich Germany),EPC 10 quadro amplifiers (HEKA, Bellmore, N.Y.) and PatchControl HT10905 (Nanion Technologies) and PatchMaster v2x73 software(HEKA) andstored on a personal computer. Gigaseals are formed and the whole-cellconfiguration is established in voltage clamp mode, and membranecurrents generated by hNa_(v)1.7 are recorded. NPC-16 chips haveresistance values between 1.0 and 2.0 MΩ when filled with pipettesolution and series resistance (<5 MΩ). Signals are sampled at 25 kHzand low pass filtered at 3 kHz.

Voltage protocols Manual Electrophysiology: After establishing thewhole-cell configuration in voltage clamp mode, voltage protocols arerun to establish the 1) test potential (V_(max)), 2) holding potential(V_(h)), and 3) the conditioning potential for each cell.

After establishing the whole-cell configuration in voltage clamp mode, astandard I-V protocol is run to determine the potential at which themaximal current (I_(max)) is elicited. This potential is the testpotential (V_(t)). To determine a conditioning potential at which 100%of channels are in the inactivated state, a standard steady-stateinactivation (SSIN) protocol is run using a series of fifteen 100ms-long depolarizing prepulses, incrementing in 10 mV steps, immediatelyfollowed by a 5 ms testing pulse to V_(max). This protocol also permitsdetermination of the holding potential at which all channels are in theresting state.

For compounds causing significant retardation of recovery frominactivation, an estimate of the affinity for the inactivated state ofthe channel (K_(i)) is generated using the following protocol. From thenegative, no residual inactivation, holding potential, the cell isdepolarized to the conditioning voltage for 2-5 seconds, returned to thenegative holding potential for 10-20 ms to relieve fast inactivation andthen depolarized to the test potential for ˜15 ins. This voltageprotocol is repeated every 10-15 seconds, first to establish a baselinein the absence of the test compound, then in the presence of the testcompound.

After a stable baseline is established, the test compound is applied andblock of the current elicited by the test pulse assessed. In some cases,multiple cumulative concentrations are applied to identify aconcentration that blocked between 40-60% of this current. Washout ofthe compound is attempted by superfusing with control solution oncesteady-state block is observed. An estimate of the K_(i) is calculatedas follows:

K _(i)=[drug]*{FR/(1−FR)},  Eq. 1

where [drug] is the concentration of a drug, and

FR=I(after drug)/1(control),  Eq. 2

where I is the peak current amplitude. If multiple concentrations wereused, K_(i) is determined from the fit of a logistic equation to FRsplotted against corresponding drug concentrations.

In the alternative, the voltage clamp protocol to examine hNa_(v)1.7currents is as follows. After establishing the whole-cell configurationin voltage clamp mode, two voltage protocols were run to establish: 1)the holding potential; and 2) the test potential for each cell.

Resting block: To determine a membrane potential at which the majorityof channels are in the resting state, a standard steady-stateinactivation (SSIN) protocol is run using 100 ms prepulses×10 mVdepolarizing steps. The holding potential for testing resting block(V_(h1)) is typically 20 V more hyperpolarized than the first potentialwhere inactivation is observed with the inactivation protocol.

From this holding potential a standard 1-V protocol is run to determinethe potential at which the maximal current is elicited (V_(max)). Thispotential is the test potential (V_(t)).

The compound testing protocol is a series of 10 ms depolarizations fromthe Vh1 (determined from the SSIN) to the V, (determined from the I-Vprotocol) repeated every 10-15 seconds. After a stable baseline isestablished, a high concentration of a test compound (highestconcentration solubility permits or that which provides ˜50% block) isapplied and block of the current assessed. Washout of the compound isattempted by superfusing with control solution once steady-state blockwas observed. The affinity for the resting state of the channels iscalculated as follows:

K _(r)=[drug]*{FR/(1−FR)},  Eq. 3

where [drug] is the concentration of a drug, and

FR=I(after drug)/I(control),  Eq. 2

where I is the peak current amplitude and was used for estimatingresting block dissociation constant, K_(r).

Block of inactivated channels: To assess the block of inactivatedchannels the holding potential is depolarized such that 20-50% of thecurrent amplitude is reduced when pulsed to the same V_(t) as above.This is the second holding potential (V_(h2)). The magnitude of thisdepolarization depends upon the initial current amplitude and the rateof current loss due to slow inactivation. The current reduction isrecorded to determine the fraction of available channels at thispotential (h).

h=I@V _(h2) /I _(max)  Eq. 4

At this membrane voltage a proportion of channels are in the inactivatedstate, and thus inhibition by a blocker includes interaction with bothresting and inactivated channels.

To determine the potency of the test compound on inactivated channels, aseries of currents are elicited by 10 ms voltage steps from V_(h2) toV_(t) every 10-15 seconds. After establishing a stable baseline, the lowconcentration of the compound is applied. In some cases, multiplecumulative concentrations will have to be applied to identify aconcentration that blocks between 40-60% of the current. Washout isattempted to re-establish baseline. Fractional responses are measuredwith respect to a projected baseline to determine K_(app):

K _(app)=[drug]*{FR/(1−FR)},  Eq. 5

where [drug] is the concentration of a drug.

This K_(app) value, along with the calculated K_(r) and h values, areused to calculate the affinity of the compound for the inactivatedchannels (K_(i)) using the following equation:

Ki=(1-h)/((1/K _(app))−(h/K _(r))).  Eq. 6

Voltage protocols Automated Electrophysiology: Similar voltage protocolsare used as described above, however the test potential (V_(t)) is setto a predetermined voltage. K_(app) is determined as described above.

Solutions and chemicals: For electrophysiological recordings theexternal solution is either standard, HBSS supplemented with 10 mM HEPES(pH adjusted to 7.34 with NaOH and the osmolarity adjusted to 320) orTyrodes salt solution (Sigma, USA) supplemented with 10 mM HEPES (pHadjusted to 7.4 with NaOH: osmolarity=320). The internal pipettesolution contains (in mM): NaCl (10), CsF (140), CaCl2 (1), MgCl2 (5),EGTA (1H). HEPES (10: pH 7.4, 305 mOsm). Compounds are prepared first asseries of stock solutions in DMSO and then dissolved in externalsolution; DMSO content in final dilutions did not exceed 0.3%. At thisconcentration. DMSO does not affect sodium currents. Vehicle solutionused to establish base line also contains 0.3% DMSO.

Data analysis Manual Electrophysiology: Data is analyzed off-line usingClampfit software (pClamp, v.8; Axon Instruments) and graphed usingGraphPad Prizm (v. 4.0) software.

Data analysis Automated Electrophysiology: Data is analyzed off-lineusing Igor Pro (v 6.2.2.2; Wave Metrics, Inc., Lake Oswego, Oreg.) andMicrosoft XL (Microsoft Office 2010, v14x. Microsoft, Renton Wash.).

In Vivo Assay for Pain

Compounds of the Invention can be tested for their antinociceptiveactivity in the formalin model as described in Hunskaar et al., J.Neurosci. Methods 14: 69-76 (1985). Male Swiss Webster NIH mice (20-30g; Harlan, San Diego, Calif.) can be used in all experiments. Food iswithdrawn on the day of the experiment. Mice are placed in Plexiglassjars for at least 1 hour to acclimate to the environment. Following theacclimation period, mice are weighed and given either the compound ofinterest administered i.p. or p.o., or the appropriate volume of vehicle(for example, 10% Tween-80 or 0.9% saline, and other pharmaceuticallyacceptable vehicles) as control. Fifteen minutes after the i.p. dosing,and 30 minutes after the p.o. dosing mice are injected with formalin (20μL of 5% formaldehyde solution in saline) into the dorsal surface of theright hind paw. Mice are transferred to the Plexiglass jars andmonitored for the amount of time spent licking or biting the injectedpaw. Periods of licking and biting are recorded in 5-minute intervalsfor 1 hour after the formalin injection. All experiments are done in ablinded manner during the light cycle. The early phase of the formalinresponse is measured as licking/biting between 0-5 minutes, and the latephase is measured from 15-50 minutes. Differences between vehicle anddrug treated groups can be analyzed by one-way analysis of variance(ANOVA). A P value <0.05 is considered significant. Compounds areconsidered to be efficacious for treating acute and chronic pain if theyhave activity in blocking both the early and second phase offormalin-induced paw-licking activity.

In Vivo Assays for Inflammatory or Neuropathic Pain

Test Animals: Each experiment uses rats weighing between 200-260 g atthe start of the experiment. The rats are group-housed and have freeaccess to food and water at all times, except prior to oraladministration of a test compound when food is removed for 16 h beforedosing. A control group acts as a comparison to rats treated with aCompound of the Invention. The control group is administered the carrieras used for the test compound. The volume of carrier administered to thecontrol group is the same as the volume of carrier and test compoundadministered to the test group.

Inflammatory Pain: To assess the actions of Compounds of the Inventionon the treatment of inflammatory pain, the Freund's complete adjuvant(“FCA”) model of inflammatory pain is used. FCA-induced inflammation ofthe rat hind paw is associated with the development of persistentinflammatory mechanical and thermal hyperalgesia and provides reliableprediction of the anti-hyperalgesic action of clinically usefulanalgesic drugs (Bartho et al., Naunyn-Schniedeberg's Archives ofPharmacol. 342:666-670 (1990)). Prior to the injury, the animal isassessed for response to noxious mechanical stimuli by determining thepaw withdrawal threshold (PWT), or to noxious thermal stimuli bydetermining paw withdrawal latency (PWL), as described below (baselinePWT or PWL). Then, the left hind paw of each animal is administered a 50μL intraplantar injection of 50% FCA. 24 hour post injection, the PWT orPWL is again assessed (pre-administration PWT or PWL). Rats are thenadministered a single injection of either a test compound or 30 mg/Kg ofa positive control compound (e.g., indomethacin). Responses to noxiousmechanical or thermal stimuli are then determined 1, 3, 5 and 24 hourspost administration (post-administration PWT or PWL). Percentagereversal of hyperalgesia for each animal is defined as:

${\% \mspace{14mu} {reversal}} = {\frac{\begin{matrix}\left\lbrack {\left( {{post}\mspace{14mu} {administration}{\; \mspace{11mu}}{PWT}\mspace{14mu} {or}{\; \mspace{11mu}}{PWL}} \right) -} \right. \\\left. \left( {{pre}\text{-}{administration}\mspace{14mu} {PWT}\mspace{14mu} {or}{\; \mspace{11mu}}{PWL}} \right) \right\rbrack\end{matrix}}{\left\lbrack {\left( {{baseline}\mspace{14mu} {PWT}\mspace{14mu} {or}\mspace{14mu} {PWL}} \right) - \left( {{pre}\text{-}{administration}{\; \mspace{11mu}}{PWT}\mspace{14mu} {or}{\; \mspace{11mu}}{PWL}} \right)} \right\rbrack} \times 100}$

Neuropathic Pain: To assess the actions of the test compounds for thetreatment of neuropathic pain the Seltzer model or the Chung model canbe used.

In the Seltzer model, the partial sciatic nerve ligation model ofneuropathic pain is used to produce neuropathic hyperalgesia in rats(Seltzer et al., Pain 43:205-218 (1990)). Partial ligation of the leftsciatic nerve is performed under isoflurane/O₂ inhalation anesthesia.Following induction of anesthesia, the left thigh of the rat is shavedand the sciatic nerve exposed at high thigh level through a smallincision and is carefully cleared of surrounding connective tissues at asite near the trocanther just distal to the point at which the posteriorbiceps semitendinosus nerve branches off of the common sciatic nerve. A7-0 silk suture is inserted into the nerve with a ⅜ curved,reversed-cutting mini-needle and tightly ligated so that the dorsal ⅓ to½ of the nerve thickness is held within the ligature. The wound isclosed with a single muscle suture (4-0 nylon (Vicryl)) and vetbondtissue glue. Following surgery, the wound area is dusted with antibioticpowder. Sham-treated rats undergo an identical surgical procedure exceptthat the sciatic nerve is not manipulated. Following surgery, animalsare weighed and placed on a warm pad until they recover from anesthesia.Animals are then returned to their home cages until behavioral testingbegins, the animals are assessed for response to noxious mechanicalstimuli by determining PWT, as described below, prior to surgery(baseline), then immediately prior to and 1, 3, and 5 hours afteradministration of either drug or vehicle, for the ipsilateral (injuredside) rear paw of the animal. Percentage reversal of neuropathichyperalgesia is defined as:

${\% \mspace{14mu} {reversal}} = {\frac{\left\lbrack {\left( {{post}\mspace{14mu} {administration}\mspace{14mu} {PWT}} \right) - \left( {{pre}\text{-}{administration}\mspace{14mu} {PWT}} \right)} \right\rbrack}{\left\lbrack {\left( {{baseline}\mspace{14mu} {PWT}} \right) - \left( {{pre}\text{-}{administration}\mspace{14mu} {PWT}} \right)} \right\rbrack} \times 100}$

In the Chung model, the spinal nerve ligation (SNL) model of neuropathicpain is used to produce mechanical hyperalgesia, thermal hyperalgesia,and tactile allodynia in rats. Surgery is performed under isoflurane/O₂inhalation anesthesia. Following induction of anesthesia a 3 cm incisionis made and the left paraspinal muscles a separated from the spinousprocess at the L₄-S₂ levels. The L₆ transverse process is carefullyremoved with a pair of small rongeurs to identify visually the L₄-L₆spinal nerves. The left L₅ (or L₅ and L₆) spinal nerve(s) is (are)isolated and tightly ligated with silk thread. A complete hemostasis isconfirmed and the wound is sutured using non-absorbable sutures, such asnylon sutures or stainless steel staples. Sham-treated rats undergo anidentical surgical procedure except that the spinal nerve(s) is (are)not manipulated. Following surgery animals are weighed, administered asubcutaneous (s.c.) injection of saline or ringers lactate, the woundarea is dusted with antibiotic powder and they are kept on a warm paduntil they recover from the anesthesia. Animals are then returned totheir home cages until behavioral testing begins. The animals areassessed for response to noxious mechanical stimuli by determining PWT,as described below, prior to surgery (baseline), then immediately priorto and 1, 3, and 5 hours after being administered a Compound of theInvention or vehicle, for the left rear paw of the animal. The animalscan also be assessed for response to noxious thermal stimuli or fortactile allodynia, as described below. The Chung model for neuropathicpain is described in Kim et al., Pain 50(3):355-363 (1992).

Tactile Allodynia: Sensitivity to non-noxious mechanical stimuli can bemeasured in animals to assess tactile allodynia. Rats are transferred toan elevated testing cage with a wire mesh floor and allowed to acclimatefor five to ten minutes. A series of von Frey monofilaments are appliedto the plantar surface of the hindpaw to determine the animal'swithdrawal threshold. The first filament used possesses a bucklingweight of 9.1 gms (0.96 log value) and is applied up to five times tosee if it elicits a withdrawal response. If the animal has a withdrawalresponse, then the next lightest filament in the series would be appliedup to five times to determine if it also could elicit a response. Thisprocedure is repeated with subsequent lesser filaments until there is noresponse and the identity of the lightest filament that elicits aresponse is recorded. If the animal does not have a withdrawal responsefrom the initial 9.1 gms filament, then subsequent filaments ofincreased weight are applied until a filament elicits a response and theidentity of this filament is recorded. For each animal, threemeasurements are made at every time point to produce an averagewithdrawal threshold determination. Tests can be performed prior to, andat 1, 2, 4 and 24 hours post drug administration.

Mechanical Hyperalgesia: Representative Compounds of the Invention canbe tested in the SNL-induced mechanical hyperalgesia model in rats.Sensitivity to noxious mechanical stimuli are measured in animals usingthe paw pressure test to assess mechanical hyperalgesia. In rats, hindpaw withdrawal thresholds (“PWT”), measured in grams, in response to anoxious mechanical stimulus are determined using an analgesymeter (Model7200, commercially available from Ugo Basile of Italy), as described inStein (Biochemistry & Behavior 31: 451-455 (1988)). The rat's paw isplaced on a small platform, and a punctuate weight was applied in agraded manner up to a maximum of 250 grams. The endpoint is taken as theweight at which the paw is completely withdrawn. PWT is determined oncefor each rat at each time point. PWT can be measured only in the injuredpaw, or in both the injured and non-injured paw. Rats are tested priorto surgery to determine a baseline, or normal, PWT. Rats are testedagain 2 to 3 weeks post-surgery, prior to, and at different times after(e.g. 1, 3, 5 and 24 hr) drug administration. An increase in PWTfollowing drug administration indicates that the test compound reducesmechanical hyperalgesia.

In Vivo Assay for Anticonvulsant Activity

Compounds of the Invention can be tested for in vivo anticonvulsantactivity after i.v., p.o., or i.p. injection using any of a number ofanticonvulsant tests in mice or rats, including the maximum electroshockseizure test (MES). Maximum electroshock seizures are induced in maleNSA mice weighing between 15-20 g and in male Sprague-Dawley ratsweighing between 200-225 g by application of current (for mice: 50 mA,60 pulses/see, 0.8 msec pulse width, 1 sec duration, D.C.; for rats: 99mA, 125 pulses/sec, 0.8 msec pulse width, 2 sec duration. D.C.) using aUgo Basile ECT device (Model 7801). Mice are restrained by gripping theloose skin on their dorsal surface and saline-coated corneal electrodesare held lightly against the two corneae. Rats are allowed free movementon the bench top and ear-clip electrodes are used. Current is appliedand animals are observed for a period of up to 30 seconds for theoccurrence of a tonic hindlimb extensor response. A tonic seizure isdefined as a hindlimb extension in excess of 90 degrees from the planeof the body. Results can be treated in a quantal manner.

Pharmaceutical Compositions

Compounds of the Invention can be administered to a mammal in the formof a raw chemical without any other components present. Compounds of theInvention can also be administered to a mammal as part of apharmaceutical composition containing the compound combined with asuitable pharmaceutically acceptable carrier. Such a carrier can beselected from pharmaceutically acceptable excipients and auxiliaries.

Pharmaceutical compositions within the scope of the Invention includeall compositions where a Compound of the Invention is combined with oneor more pharmaceutically acceptable carriers. In one embodiment, theCompound of the Invention is present in the composition in an amountthat is effective to achieve its intended therapeutic purpose. Whileindividual needs may vary, a determination of optimal ranges ofeffective amounts of each compound is within the skill of the art.Typically, a Compound of the Invention can be administered to a mammal,e.g., a human, orally at a dose of from about 0.0025 to about 1500 mgper kg body weight of the mammal, or an equivalent amount of apharmaceutically acceptable salt or solvate thereof, per day to treatthe particular disorder. A useful oral dose of a Compound of theInvention administered to a mammal is from about 0.0025 to about 50 mgper kg body weight of the mammal, or an equivalent amount of thepharmaceutically acceptable salt or solvate thereof. For intramuscularinjection, the dose is typically about one-half of the oral dose.

A unit oral dose may comprise from about 0.01 mg to about 1 g of theCompound of the Invention, e.g., about 0.01 ng to about 500 mg, about0.01 mg to about 250 mg, about 0.01 mg to about 100 mg, 0.01 mg to about50 mg, e.g., about 0.1 mg to about 10 mg, of the compound. The unit dosecan be administered one or more times daily, e.g., as one or moretablets or capsules, each containing from about 0.01 mg to about 1 g ofthe compound, or an equivalent amount of a pharmaceutically acceptablesalt or solvate thereof.

A pharmaceutical composition of the Invention can be administered to anyanimal that may experience the beneficial effects of a Compound of theInvention. Foremost among such animals are mammals, e.g., humans andcompanion animals, although the Invention is not intended to be solimited.

A pharmaceutical composition of the Invention can be administered by anymeans that achieves its intended purpose. For example, administrationcan be by the oral, parenteral, subcutaneous, intravenous,intramuscular, intraperitoneal, transdermal, intranasal, transmucosal,rectal, intravaginal or buccal route, or by inhalation. The dosageadministered and route of administration will vary, depending upon thecircumstances of the particular subject, and taking into account suchfactors as age, gender, health, and weight of the recipient, conditionor disorder to be treated, kind of concurrent treatment, if any,frequency of treatment, and the nature of the effect desired.

In one embodiment, a pharmaceutical composition of the Invention can beadministered orally and is formulated into tablets, dragees, capsules oran oral liquid preparation. In one embodiment, the oral formulationcomprises extruded multiparticulates comprising the Compound of theInvention.

Alternatively, a pharmaceutical composition of the Invention can beadministered rectally, and is formulated in suppositories.

Alternatively, a pharmaceutical composition of the Invention can beadministered by injection.

Alternatively, a pharmaceutical composition of the Invention can beadministered transdermally.

Alternatively, a pharmaceutical composition of the Invention can beadministered by inhalation or by intranasal or transmucosaladministration.

Alternatively, a pharmaceutical composition of the Invention can beadministered by the intravaginal route.

A pharmaceutical composition of the Invention can contain from about0.01 to 99 percent by weight, and preferably from about 0.25 to 75percent by weight, of active compound(s).

A method of the Invention, such as a method for treating a disorderresponsive to the blockade of sodium channels in an animal in needthereof, can further comprise administering a second therapeutic agentto the animal in combination with a Compound of the Invention. In oneembodiment, the other therapeutic agent is administered in an effectiveamount.

Effective amounts of the other therapeutic agents are known to thoseskilled in the art. However, it is well within the skilled artisan'spurview to determine the other therapeutic agent's optimaleffective-amount range.

Compounds of the Invention (i.e., the first therapeutic agent) and thesecond therapeutic agent can act additively or, in on embodiment,synergistically. Alternatively, the second therapeutic agent can be usedto treat a disorder or condition that is different from the disorder orcondition for which the first therapeutic agent is being administered,and which disorder or condition may or may not be a condition ordisorder as defined herein. In one embodiment, a Compound of theInvention is administered concurrently with a second therapeutic agent;for example, a single composition comprising both an effective amount ofa Compound of the Invention and an effective amount of the secondtherapeutic agent can be administered. Accordingly, the Inventionfurther provides a pharmaceutical composition comprising a combinationof a Compound of the Invention, the second therapeutic agent, and apharmaceutically acceptable carrier. Alternatively, a firstpharmaceutical composition comprising an effective amount of a Compoundof the Invention and a second pharmaceutical composition comprising aneffective amount of the second therapeutic agent can be concurrentlyadministered. In another embodiment, an effective amount of a Compoundof the Invention is administered prior or subsequent to administrationof an effective amount of the second therapeutic agent. In thisembodiment, the Compound of the Invention is administered while thesecond therapeutic agent exerts its therapeutic effect, or the secondtherapeutic agent is administered while the Compound of the Inventionexerts its therapeutic effect for treating a disorder or condition.

The second therapeutic agent can be an opioid agonist, a non-opioidanalgesic, a non-steroidal anti-inflammatory agent, an antimigraineagent, a Cox-II inhibitor, a β-adrenergic blocker, an anticonvulsant, anantidepressant, an anticancer agent, an agent for treating addictivedisorder, an agent for treating Parkinson's disease and parkinsonism, anagent for treating anxiety, an agent for treating epilepsy, an agent fortreating a seizure, an agent for treating a stroke, an agent fortreating a pruritic condition, an agent for treating psychosis, an agentfor treating ALS, an agent for treating a cognitive disorder, an agentfor treating a migraine, an agent for treating vomiting, an agent fortreating dyskinesia, or an agent for treating depression, or a mixturethereof.

A pharmaceutical composition of the Invention is manufactured in amanner which itself will be known in view of the instant disclosure, forexample, by means of conventional mixing, granulating, dragee-making,dissolving, extrusion, or lyophilizing processes. Thus, pharmaceuticalcompositions for oral use can be obtained by combining the activecompound with solid excipients, optionally grinding the resultingmixture and processing the mixture of granules, after adding suitableauxiliaries, if desired or necessary, to obtain tablets or dragee cores.

Suitable excipients include fillers such as saccharides (for example,lactose, sucrose, mannitol or sorbitol), cellulose preparations, calciumphosphates (for example, tricalcium phosphate or calcium hydrogenphosphate), as well as binders such as starch paste (using, for example,maize starch, wheat starch, rice starch, or potato starch), gelatin,tragacanth, methyl cellulose, hydroxypropylmethylcellulose, sodiumcarboxymethylcellulose, and/or polyvinyl pyrrolidone. If desired, one ormore disintegrating agents can be added, such as the above-mentionedstarches and also carboxymethyl-starch, cross-linked polyvinylpyrrolidone, agar, or alginic acid or a salt thereof, such as sodiumalginate.

Auxiliaries are typically flow-regulating agents and lubricants such as,for example, silica, talc, stearic acid or salts thereof (e.g.,magnesium stearate or calcium stearate), and polyethylene glycol. Drageecores are provided with suitable coatings that are resistant to gastricjuices. For this purpose, concentrated saccharide solutions can be used,which may optionally contain gum arabic, talc, polyvinyl pyrrolidone,polyethylene glycol and/or titanium dioxide, lacquer solutions andsuitable organic solvents or solvent mixtures. In order to producecoatings resistant to gastric juices, solutions of suitable cellulosepreparations such as acetylcellulose phthalate orhydroxypropylmethyl-cellulose phthalate can be used. Dye stuffs orpigments can be added to the tablets or dragee coatings, for example,for identification or in order to characterize combinations of activecompound doses.

Examples of other pharmaceutical preparations that can be used orallyinclude push-fit capsules made of gelatin, or soft, sealed capsules madeof gelatin and a plasticizer such as glycerol or sorbitol. The push-fitcapsules can contain a compound in the form of granules, which can bemixed with fillers such as lactose, binders such as starches, and/orlubricants such as talc or magnesium stearate and, optionally,stabilizers, or in the form of extruded multiparticulates. In softcapsules, the active compounds are preferably dissolved or suspended insuitable liquids, such as fatty oils or liquid paraffin. In addition,stabilizers can be added.

Possible pharmaceutical preparations for rectal administration include,for example, suppositories, which consist of a combination of one ormore active compounds with a suppository base. Suitable suppositorybases include natural and synthetic triglycerides, and paraffinhydrocarbons, among others. It is also possible to use gelatin rectalcapsules consisting of a combination of active compound with a basematerial such as, for example, a liquid triglyceride, polyethyleneglycol, or paraffin hydrocarbon.

Suitable formulations for parenteral administration include aqueoussolutions of the active compound in a water-soluble form such as, forexample, a water-soluble salt, alkaline solution, or acidic solution.Alternatively, a suspension of the active compound can be prepared as anoily suspension. Suitable lipophilic solvents or vehicles for such assuspension may include fatty oils (for example, sesame oil), syntheticfatty acid esters (for example, ethyl oleate), triglycerides, or apolyethylene glycol such as polyethylene glycol-400 (PEG-400). Anaqueous suspension may contain one or more substances to increase theviscosity of the suspension, including, for example, sodiumcarboxymethyl cellulose, sorbitol, and/or dextran. The suspension mayoptionally contain stabilizers.

The following examples are illustrative, but not limiting, of thecompounds, compositions, and methods of the Invention. Suitablemodifications and adaptations of the variety of conditions andparameters normally encountered in clinical therapy and which areobvious to those skilled in the art in view of this disclosure arewithin the spirit and scope of the Invention.

EXAMPLES Example 1 Synthesis of(S)-6-((1-amino-1-oxopropan-2-yl)amino)-2-chloropyrimidine-4-carboxamide(Compound 5)

A mixture of Compound 1 (34.828 g, 0.200 mol, Sigma-Aldrich), phosphorusoxychloride (100 mL, 1.092 mol) and 20 drops of DMF were heated at 110°C. overnight. After cooling to RT the dark mixture was diluted withhexanes (500 mL) and vigorously stirred. The hexane layer was decanted,quickly washed with water (100 mL), brine (100 mL) and dried over MgSO₄.The organic layer was filtered and carefully evaporated in vacuo to giveCompound 2 as a light yellow liquid (26.13 g). Yield 62%

¹H NMR (400 MHz, CDCl₃): δ 7.93 (s, 1H).

To a solution of Compound 2 (26.13 g, 123.6 mmol) in Et₂O (500 mL) wasadded a mixture of 0.5M NH₃ in dioxane (250 mL, 125 mmol) and DIPEA (22mL, 126 mmol) dropwise over 50 min. After stirring at RT overnight thereaction mixture was concentrated in vacuo to give a residue that waspurified by flash chromatography (SiO₂, 10-50% EtOAc/hexanes). Theproduct obtained was triturated with 10 mL 10% EctOAc/hexanes andfiltered to give Compound 3 as an orange crystalline solid (9.74 g).Yield 41%

¹H NMR (400 MHz, DMSO-d₆): δ 8.40 (br s, 1H), 8.16 (br s, 1H), 8.10 (s,1H); LC/MS: m/z=192.2 [M+H]⁺ (Calc: 191.4).

To a solution of Compound 3 (4.80 g, 25.0 mmol) in ACN (100 ml) wasadded (S)-2-aminopropane carboxamide hydrochloride (Compound 4) (3.18 g,25.54 mmol) and DIPEA (9.60 mL, 55.11 mmol). The mixture was heated at50° C. overnight then concentrated in vacuo. The residue was purified byflash chromatography (SiO₂, 20-60% acetone/hexanes) to give Compound 5as a pale tan powder (4.81 g). Yield 79%; LC/MS: m/z=244.5 [M+H]⁺ (Calc:243.7).

Example 2 Synthesis of(2R,3S)-3-(6-bromopyridin-2-yl)-2,3-dihydroxypropanamide (Compound 10)

To a suspension of NaH (60% in mineral oil, 0.77 g, 19.4 mmol) in THF(50 mL) at 0° C. was slowly added Compound 7 (3.2 mL, 16.1 mmol). Gasevolution occurred and most of the solids dissolved. The reaction wasstirred at 0° C. for 15 min then Compound 6 (3.00 g, 16.1 mmol) wasadded in several small portions. The reaction mixture was stirred at 0°C. for 15 min then warmed to RT and stirred overnight. The reaction wascarefully quenched with water and extracted with EtOAc (2×). Thecombined organic layers were dried over MgSO₄ and concentrated. Theresidue was purified by flash chromatography (SiO₂, 0-20% EtOAc/hexanes)to afford Compound 8 as a white solid (2.30 g, yield 56%).

¹H NMR (400 MHz, CDCl₃) δ: 7.55-7.62 (m, 2H), 7.46 (d, J=7.5 Hz. 1H),7.37 (d, J=7.5 Hz, 1H), 6.97 (d, J=15.6 Hz, 1H), 4.29 (q, J=7.3 Hz, 2H),1.35 (t, J=7.3 Hz, 3H): LC/MS: m/z=256.0/258.0 [M+H]⁺ (Calc: 256.1).

To a solution of Compound 8 (2.30 g, 8.98 mmol) in t-BuOH (40 mL) andwater (40 mL) at 0° C. was added AD-mix-alpha (12.6 g; 1.4 g/mmol ofvinyl substrate, Sigma-Aldrich). The reaction mixture was stirred at RTovernight then diluted with water and extracted with EtOAc (3×). Thecombined organic extracts were washed with brine, dried over MgSO₄ andconcentrated. The residue was purified by flash chromatography (SiO₂,50% EtOAc/hexanes) to provide Compound 9 as a white solid (1.68 g, yield65%).

¹H NMR (400 MHz, CDCl₃) δ: 7.59-7.64 (m, 1H), 7.45 (d, J=7.7 Hz, 2H),5.11 (dd, J=8.1, 2.4 Hz, 1H), 4.63 (dd, J=6.4, 2.4 Hz, 1H), 4.35 (q,J=7.2 Hz, 2H), 3.78 (d, J=8.1 Hz, 1H), 3.25 (d, J=6.4 Hz, 1H), 1.36 (t,J=7.2 Hz, 3H); LC/MS: m/z=290.0/292.0 [M+H]⁺ (Calc: 290.1).

To a flask containing Compound 9 (1.20 g, 4.14 mmol) was added 7M NH inMeOH (15 ml. 105 mmol). The flask was capped with a rubber septum andthe reaction was stirred at RT overnight. The reaction was concentratedto afford pure Compound 10 as a white solid (1.05 g. yield 97%).

¹H NMR (400 MHz, MeOH-d₄) δ: 7.71 (t, J=7.7 Hz, 1H), 7.63 (d, J=7.7 Hz,1H), 7.47 (d, J=7.7 Hz. 1H), 5.12 (d, J=1.8 Hz, 1H), 4.50 (d, J=1.8 Hz,1H); LC/MS: m/z=261.0/263.0 [M+H]⁺ (Calc: 261.1).

Example 3 Synthesis of6-bromo-N-(1,2,4-thiadiazol-5-yl)pyridine-2-sulfonamide (Compound 13)

To a solution of Compound 12 (0.079 g, 0.780 mmol) and TEA (0.24 ml,1.715 mmol) in DCM (5 mL) cooled to 0° C. was added Compound 11 (0.20 g,0.780 mmol). The mixture was stirred at 0° C. for 1 h, quenched withwater and extracted with DCM. The organic extracts were dried over MgSO₄and concentrated to give Compound 13 as an orange oil that was used insubsequent steps without purification (0.21 g, yield 84%): LC/MS:m/z=322.8 [M+H]⁺ (Calc: 321.2).

Example 4 Synthesis of tert-butyl5-(4-(trifluoromethyl)phenyl)-3,4-dihydroisoquinoline-2(1H)-carboxylate(Compound 16)

Argon was bubbled through a mixture of Compound 14 (2.00 g, 5.57 mmol,ASW MedChem), Compound 15 (1.51 g, 5.57 mmol), Pd(PPh₃)Cl₂ (195 mg, 0.28mmol) and Cs₂CO₃ (3.63 g. 11.13 mmol) in 2:2:1 DME/EtOH/water (10) mL)for 1 min. The mixture was heated at 85° C. for 16 h, cooled to RT andDCM and water were added. The layers were separated and the aqueouslayer extracted with DCM. The combined organic extracts were washed withwater, dried over MgSO₄ and concentrated. The residue was purified byflash chromatography (SiO₂, 100% EtOAc/hexanes) to provide Compound 16as an off-white foam (1.28 g, yield 61%): LC/MS: n/z=400.2 [M+Na]⁺(Calc: 377.4).

In a similar manner, the following compounds were prepared:

tert-Butyl5-(5-(trifluoromethyl)pyridin-2-yl)-3,4-dihydroisoquinoline-2(1H)-carboxylate(Compound 17): LC/MS: m/z=379.2 [M+H]⁺ (Calc: 378.4).

tert-Butyl5-(2-(trifluoromethyl)phenyl)-3,4-dihydroisoquinoline-2(1H)-carboxylate(Compound 18): LC/MS: m/z=378.2 [M+H]⁺ (Calc: 377.4).

tert-Butyl5-(3-(trifluoromethyl)phenyl)-3,4-dihydroisoquinoline-2(1H)-carboxylate(Compound 19): LC/MS: m/z=378.2 [M+H]⁺ (Calc: 377.4).

tert-Butyl5-(cyclohex-1-en-1-yl)-3,4-dihydroisoquinoline-2(1H)-carboxylate(Compound 20): LCMS: n/z=314.2 [M+H]⁺ (Calc: 313.4).

Example 5 Preparation of TFA salt of(S)-6-((1-amino-1-oxopropan-2-yl)amino)-2-(5-(4-(trifluoromethyl)phenyl)-3,4-dihydroisoquinolin-2(1H)-yl)pyrimidine-4-carboxamide(Compound 22)

TFA (2.0 mL) was added to a solution of Compound 16 (1.28 g, 3.39 mmol)in DCM (20 mL) at 0° C. The mixture was stirred at RT for 16 h, cooledto 0° C. and 1M aq. NaOH (20 mL) was added. The layers were separatedand the aqueous layer extracted with DCM.

The combined organic extracts were washed with water, dried over MgSO₄and concentrated to give Compound 21 as a yellow oil that was useddirectly in the next step without purification.

Compound 21: LC/MS: n/z=278.2 [M+H]⁺ (Calc: 277.3).

A mixture of Compound 21 (100 mg, 0.361 mmol), Compound 5 (88 mg, 0.361mmol) and Cs₂CO₃ (353 mg, 1.08 mmol) in DMF was stirred at 100° C. for16 h. The mixture was concentrated and the residue purified byreverse-phase prep HPLC (C18, 0-100% 0.1% TFA in ACN/0.1% TFA in water)to give TFA salt of Compound 22 as a white solid (85 mg). Yield 39%: ¹HNMR (400 MHz, MeOH-d₄): δ 7.66 (d, J=8.1 Hz, 2H), 7.43 (d, J=7.9 Hz,2H), 7.23-7.26 (m, 2H), 7.10-7.16 (m, 1H), 6.51 (s, 1H), 4.88 (d, J=6.6Hz, 2H), 4.40 (d, J=7.0 Hz, 1H), 3.73-3.84 (m, 2H), 2.74-2.84 (m, 2H),1.42 (d, J=7.3 Hz, 3H); LC/MS: m/z=485.1 [M+H]⁺ (Calc: 484.5).

In a similar manner, the following compounds were prepared:

Bis TFA salt of(S)-6-((1-amino-1-oxopropan-2-yl)amino)-2-((5-(trifluoromethyl)-pyridin-2-yl)-3,4-dihydroisoquinolin-2(1H)-yl)pyrimidine-4-carboxamide(Compound 23):

¹H NMR (400 MHz, MeOH-d₄): δ 8.87 (d, J=0.7 Hz, 1H), 8.15 (dd, J=8.1,2.2 Hz, 1H), 7.66 (d, J=8.1 Hz, 1H), 7.27-7.37 (m, 3H), 6.53 (s, 1H),4.83-4.98 (m, 2H), 4.44 (q, J=6.5 Hz, 1H), 3.79 (br. s., 2H), 2.88-3.05(m, 2H), 1.37-1.49 (m, 3H); LC/MS: m/z=486.1 [M+H]⁺ (Calc: 485.5).

TFA salt of(S)-6-((1-amino-1-oxopropan-2-yl)amino)-2-(5-(2-(trifluoromethyl)-phenyl)-3,4-dihydroisoquinolin-2(1H)-yl)pyrimidine-4-carboxamide(Compound 24):

¹H NMR (400 MHz, MeOH-d₄): δ 7.72 (d, J=7.9 Hz, 1H), 7.54-7.61 (n, 1),7.46-7.52 (m, 1H), 7.16-7.26 (m, 3H), 7.00 (d, J=7.3 Hz. 1H), 6.51 (s,1H), 4.82-4.97 (m, 2H), 4.40 (d, J=6.6 Hz, 1H), 3.89 (d, J=5.5 Hz, 1H),3.61 (ddd, J=12.2, 7.5, 4.5 Hz, 1H), 2.50-2.61 (m, 1H), 2.35-2.46 (m,1H), 1.38-1.45 (m, 3H); LC/MS: m/z=485.1 [M+H]⁺ (Calc: 484.5).

TFA salt of6-(5-(4-(trifluoromethyl)phenyl)-3,4-dihydroisoquinolin-2(1H)-yl)picolinamide(Compound 25):

¹H NMR (400 MHz, DMSO-d₆): δ 7.95-8.03 (m, 1H), 7.75 (d, J=8.1 Hz, 211),7.63 (t, J=7.9 Hz, 1H), 7.54 (d, J=7.9 Hz, 2H), 7.48 (hr. s., 1H),7.31-7.36 (m, 1H), 7.25-7.30 (m, 1H), 7.22 (d, J=7.0 Hz, 1H), 7.12 (d,J=7.3 Hz, 1H), 6.94 (d, J=8.6 Hz, 1H), 4.80 (s, 2H), 3.69 (t, J=5.7 Hz,2H), 2.72 (t, J=5.6 Hz, 2H); LC/MS: m/z=398.1 [M+H]⁺ (Calc: 397.4).

TFA salt of(2S,3R)-2,3-dihydroxy-3-(6-(5-(4-(trifluoromethyl)phenyl)-3,4-dihydroisoquinolin-2(1H)-yl)pyridin-2-yl)propanamide(Compound 26):

¹H NMR (400 MHz, MeOH-d₄): δ 7.90 (dd, J=9.1, 7.4 Hz, 1H), 7.68 (d,J=8.1 Hz, 2H), 7.47 (d, J=8.1 Hz, 2H), 7.27-7.33 (m, 2H), 7.15-7.24 (m,2H), 6.98 (d, J=7.3 Hz, 1H), 5.07 (d, J=3.3 Hz, 1H), 4.81 (s. 2H), 4.29(d, J=3.5 Hz, 1H), 3.68 (t, J=5.9 Hz, 2H), 2.94 (t, J=5.9 Hz, 2H);LC/MS: n/z=458.1 [M+H]⁺ (Calc: 457.4).

Bis TFA salt of(S)-6-((1-amino-1-oxopropan-2-yl)amino)-2-(5-(3-(trifluoromethyl)phenyl)-3,4-dihydroisoquinolin-2(1H)-yl)pyrimidine-4-carboxamide(Compound 27):

¹H NMR (400 MHz, MeOH-d₄): δ 7.53-7.63 (m, 2H), 7.49-7.53 (m, 2H),7.23-7.30 (m, 2H), 7.12-7.17 (m, 1H), 6.54 (s, 1H), 4.82-4.95 (m, 2H),4.44 (q, J=6.8 Hz, 1H), 3.76 (br. s., 2H), 2.75-2.87 (m, 2H), 1.43 (d,J=7.0 Hz, 3H); LC/MS: m/c=485.1 [M+H]⁺ (Calc: 484.5).

TFA salt of(S)-6-((1-amino-1-oxopropan-2-yl)amino)-2-(5-(cyclohex-1-en-1-yl)-3,4-dihydroisoquinolin-2(1H)-yl)pyrimidine-4-carboxamide(Compound 28):

¹H NMR (400 MHz, DMSO-d₆): δ 7.97 (br, s, 1H), 7.58-7.74 (m, 1H), 7.53(br, s, 1H), 7.38 (br, s, 1H), 7.02-7.12 (m, 2H), 6.88 (d, J=5.7 Hz.2H), 6.41 (br, s, 1H), 5.45 (br, s, 1H), 4.69-4.92 (m, 2H), 4.30-4.39(m, 1H), 3.84-3.94 (m, 1H), 3.70-3.80 (m, 1H), 2.66-2.75 (m, 2H), 2.07(d, J=4.1 Hz, 4H), 1.53-1.70 (m, 4H), 1.25 (d, J=7.1 Hz, 3H); LC/MS:m/z=421.2 [M+H]⁺ (Calc: 420.5).

TFA salt ofN-(1,2,4-thiadiazol-5-yl)-6-(5-(4-(trifluoromethyl)phenyl)-3,4-dihydroisoquinolin-2(1H)-yl)pyridine-2-sulfonamide(Compound 29):

¹H NMR (400 MHz, DMSO-d₆): δ 8.45 (s, 1H), 7.75 (d, J=8.1 Hz, 2H), 7.69(dd, J=8.5, 7.5 Hz, 1H), 7.52 (d, J=8.0 Hz, 2H), 7.23-7.30 (m, 1H), 7.12(d, J=7.3 Hz, 1H), 6.99-7.09 (m, 3H), 6.32-6.67 (m, 1H), 4.59 (s, 2H),3.54-3.59 (m, 2H), 2.66 (t, J=5.7 Hz, 2H); LC/MS: n/z=518.1 [M+H]⁺(Calc: 517.6).

6-Chloro-4-(5-(4-(trifluoromethyl)phenyl)-3,4-dihydroisoquinolin-2(1H)-yl)picolinonitrile(Compound 30): LC/MS: m/z=414.2 [M+H]⁺ (Calc: 413.8).

Example 6 Preparation of TFA salt of(S)-6-((1-amino-1-oxopropan-2-yl)amino)-2-(5-cyclohexyl-3,4-dihydroisoquinolin-2(1H)-yl)pyrimidine-4-carboxamide(Compound 31)

A solution of Compound 28 (0.40 g, 0.951 mmol) in 20% AcOH/MeOH (20 mL)was added 10% Pd/C (0.10 g) and the mixture hydrogenated at 60 psi for19 h. The mixture was filtered through Celite and concentrated. Theresidue was purified by reverse-phase prep HPLC (C18, 0-100% 0.1% TFA inACN/0.1% TFA in water) to give TFA salt of Compound 31 as a white solid(0.29 g, yield 57%).

¹H NMR (400 MHz, MeOH-d₄): δ 7.10 (d, J=4.5 Hz, 2H), 6.95-7.01 (m, 1H),6.51 (s, 1H), 4.79-4.85 (m, 2H), 4.44 (q, J=7.0 Hz, 1H), 3.80-3.92 (m,2H), 2.86-2.98 (m, 2H), 2.64-2.75 (m, 1H), 1.78 (d, J=5.8 Hz, 2H),1.65-1.74 (m, 3H), 1.44 (d, J=7.2 Hz, 3H), 1.16-1.41 (m, 5H): LC/MS:m/z=423.2 [M+H]⁺ (Calc: 422.5).

Example 7 Preparation of TFA salt of(S)-6-(1,2-dihydroxyethyl)-4-(5-(4-(trifluoromethyl)phenyl)-3,4-dihydroisoquinolin-2(1H)-yl)picolinamide(Compound 35)

Compound 35 was prepared from Compound 30 in a manner similar to thosedescribed in PCT publication No. WO 2012/035421 A2. Compound 35: ¹H NMR(400 MHz, DMSO-d₆): δ 8.74 (br, s, 1H), 8.33 (br, s, 1H), 7.78 (d, J=8.1Hz, 2H), 7.64-7.72 (m, 1H), 7.56 (d, J=7.9 Hz. 2H), 7.31-7.40 (m, 2H),7.11-7.26 (m, 2H), 4.80-4.91 (m, 3H), 3.67-3.76 (m, 2H), 3.55-3.64 (m,2H), 2.88 (t, J=5.7 Hz, 2H); C/MS: r/z=458.1 [M+H]⁺ (Calc: 457.4).

In a similar manner, the following compound was prepared:

TFA salt of(R)-6-(1,2-dihydroxyethyl)-4-(5-(4-(trifluoromethyl)phenyl)-3,4-dihydro-isoquinolin-2(1H)-yl)picolinamide(Compound 36):

¹H NMR (400 MHz, DMSO-d₆): δ 8.75 (br, s, 1H), 8.33 (br, s, 1H), 7.78(d, J=8.1 Hz, 2H), 7.65-7.72 (m, 1H), 7.56 (d, J=7.9 Hz, 2H), 7.30-7.39(m, 2H), 7.10-7.26 (m, 2H), 4.79-4.91 (m, 3H), 3.67-3.76 (m, 2H),3.54-3.66 (m, 2H), 2.88 (t, J=5.7 Hz, 2H). LC/MS: m/z=458.1 [M+H]⁺(Calc: 457.4).

Example 8

Representative Compounds of the Invention have been tested in the FLIPR®or FLIPR^(TETRA)® assay and/or EP assays for sodium channel blockingactivity. The assays are described in detail above.

Representative values obtained from the assays are presented in TABLE 3.

TABLE 3 Evaluation of compounds as sodium channel (Na_(v)) blockersNa_(v)1.7 Activity (μM) Na_(v)1.7 Activity (μM) FLIPR assay EP assayCompound IC₅₀ K_(i) 22 0.428 ± 0.069 0.317 ± 0.079 23 >20 24 2.354 ±0.125 25 0.987 ± 0.072 26 0.251 ± 0.017 0.051 ± 0.014 27 1.523 ± 0.1220.240 ± 0.041 28 2.836 ± 0.112 29 0.291 ± 0.019 0.535 ± 0.145 31 2.198 ±0.898 35 0.502 ± 0.031 0.232 ± 0.065 36 1.539 ± 0.229 0.257 ± 0.046

Having now fully described this disclosure, it will be understood bythose of ordinary skill in the art that the same can be performed withina wide and equivalent range of conditions, formulations and otherparameters without affecting the scope of the disclosure or anyembodiment thereof.

Other embodiments of the disclosure will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims.

All patents and publications cited herein are fully incorporated byreference in their entirety.

We/I claim:
 1. A compound of Formula I, or a pharmaceutically acceptable salt, solvate, hydrate, N-oxide, or diastereomer thereof:

Wherein a and b, each independently, are 0, 1, or 2, provided that at least one of a and b is a value other than 0; n, each independently, is 0, 1, or 2; m, each independently, is 0, 1, or 2; k, each independently, is 1, 2, or 3; W¹, W², and W³, each independently, are CR⁶ or N, provided that at least one of W¹, W² and W³ is N; One of R¹ and R² is H, cyano, —C(O)N(R^(a))(R^(b)), —S(O)₂N(R^(a))(R^(b)), —C(O)OR⁷, —OC(O)R⁷, —OR⁷, —[CH(R^(c))]_(n)R⁸, or —N(R^(d))(R^(e)), the other is selected from the group consisting of H, —C(O)N(R^(a))(R^(b)), —S(O)₂N(R^(a))(R^(b)), —C(O)OR⁷, —OC(O)R⁷, —OR⁷, —[CH(R^(c))]_(n)R⁸, —N(R^(d))(R^(e)), —S(O)_(m)—R^(f), ureido, halogen, cyano, and nitro; provided that R¹ and R² cannot be both H; R³ is H, alkyl, haloalkyl, —S(O)_(m)—R^(f), alkoxy, haloalkoxy, carboxamido, cyano, (carboxamido)alkyl, (hydroxy)alkyl, (dihydroxy)alkyl, nitro, optionally-substituted cycloalkyl, optionally-substituted heterocyclyl, (heterocyclyl)amino, sulfonamido, [(heterocyclyl)amino]alkyl, (alkoxy)alkyl, optionally-substituted aryl, or optionally-substituted heteroaryl, provided that when a is 2 and b is 0, then R³ is a group other than H; R⁴ and R⁵, each independently, are H, alkyl, haloalkyl, —S(O)_(m)—R^(f), alkoxy, haloalkoxy, amino, (alkyl)amino, (dialkyl)amino, carboxamido, cyano, hydroxyl, halogen, (hydroxy)alkyl, (dihydroxy)alkyl, nitro, or sulfonamido; R⁶, each independently, is H, alkyl, hydroxyl, (hydroxyl)alkyl, (dihydroxy)alkyl, amino, (alkyl)amino, (dialkyl)amino, haloalkyl, alkoxy, carboxamido, or sulfonamido; J¹ is absent, —S(O)₂—, —C(O)—, or —(CHR⁹)_(k)—; J² is absent, —S(O)₂—, or —C(O)—: A is selected from the group consisting of a) optionally-substituted alkyl; b) optionally-substituted alkoxy; c) optionally-substituted aryl; d) optionally-substituted heteroaryl; e) optionally-substituted cycloalkyl; f) optionally-substituted heterocyclyl; and g) —N(R¹⁰)(R¹¹); R⁷, each independently, is H, optionally-substituted alkyl, optionally-substituted cycloalkyl, or optionally-substituted heterocyclyl; R⁸, each independently, is H, optionally-substituted alkyl, optionally-substituted cycloalkyl, optionally-substituted heterocyclyl, or —C(O)N(R¹²)(R¹³); R⁹, each independently, is H or optionally-substituted alkyl; R¹⁰ and R¹¹, each independently, are H, optionally-substituted alkyl, optionally-substituted (alkyl)carbonyl, optionally-substituted (cycloalkyl)carbonyl, optionally-substituted (heterocyclyl)carbonyl, optionally-substituted heterocyclyl, or optionally-substituted cycloalkyl, provided that R¹⁰ and R¹¹ cannot be both H; or R¹⁰ and R¹¹, taken together with the nitrogen atom to which they are attached, form a 3- to 8-membered optionally substituted heterocyclyl; One of R¹² and R¹³ is H, the other is H, optionally-substituted alkyl, optionally-substituted heterocyclyl, or optionally-substituted cycloalkyl; or R¹² and R¹³, taken together with the nitrogen atom to which they are attached, form a 3- to 8-membered optionally substituted heterocyclyl; R^(a), on each occurrence, independently is H, optionally-substituted alkyl, optionally-substituted heterocyclyl, optionally-substituted aryl, optionally-substituted cycloalkyl, or optionally-substituted heteroaryl; R^(b), on each occurrence, independently is H, optionally-substituted alkyl, optionally-substituted heterocyclyl, optionally-substituted aryl, optionally-substituted cycloalkyl, or optionally-substituted heteroaryl; Or R^(a) and R^(b), taken together with the nitrogen atom to which they both are attached, form a 3- to 8-membered optionally substituted heterocyclyl; R^(c), each independently, is H, hydroxyl, or alkoxy; R^(d) and R^(e), each independently, are H, carboxamido, optionally-substituted (alkyl)carbonyl, optionally-substituted alkyl, optionally-substituted heterocyclyl, optionally-substituted (heterocyclyl)carbonyl, optionally-substituted aryl, optionally-substituted cycloalkyl, optionally-substituted (alkyl)sulfonyl, or optionally-substituted heteroaryl: or R^(d) and R^(c), taken together with the nitrogen atom to which they both are attached, form a 3- to 8-membered optionally substituted heterocyclyl; and R^(f), each independently, is optionally-substituted alkyl, optionally-substituted cycloalkyl, or optionally-substituted heterocyclyl; Provided that when J² is absent and A is optionally-substituted alkyl, then said optionally-substituted alkyl is unsubstituted or substituted by one to three substituents independently selected from the group consisting of amino, (alkyl)carbonyl, (aryl)carbonyl, (alkoxy)carbonyl, carboxy, aryl, heteroaryl, ureido, guanidino, halogen, sulfonamido, hydroxyl, (alkyl)sulfanyl, haloalkoxy, cycloalkyl, (alkyl)sulfonyl, and caboxamido.
 2. The compound of claim 1, wherein a is 1, and b is
 1. 3. The compound of any one of claims 1 to 2, wherein J¹ is absent.
 4. The compound of any one of claims 1 to 3, wherein J² is absent.
 5. The compound of any one of claims 1 to 4, wherein W³ is CR⁶.
 6. The compound of any one of claims 1 to 4, wherein W³ is N.
 7. The compound of any one of claims 1 to 4, wherein said compound is of Formula II or a pharmaceutically acceptable salt, solvate, hydrate, N-oxide, or diastereomer thereof:

Wherein n is 0, 1, or 2; W¹, W², and W³, each independently, are CH or N, provided that at least one of WI, W² and W³ is N; A is selected from the group consisting of phenyl, 5- to 6-membered heteroaryl, and saturated or unsaturated cyclo(C₅₋₆)alkyl, wherein each of said phenyl, said 5- to 6-membered heteroaryl, and said saturated or unsaturated cyclo(C₅₋₆)alkyl is optionally substituted by one or two substituents independently selected from the group of i) alkyl optionally substituted by one or three substituents independently selected from the group of halogen, amino, (alkyl)amino, (dialkyl)amino, hydroxyl, carboxamido, (alkoxy)carbonyl, [(alkoxy)carbonyl]amino, carboxy, alkoxy, haloalkoxy, optionally-substituted cycloalkyl, optionally-substituted heterocyclyl, and sulfonamido, wherein said cycloalkyl and said heterocyclyl, each independently, are optionally substituted by one or two substituents independently selected from the group consisting of hydroxyl, halogen, amino, (alkyl)amino, carboxamido, alkyl, haloalkyl, carboxy, (carboxy)alkyl, (carboxamido)alkyl, (alkyl)carbonyl, (alkoxy)carbonyl, and alkoxy; ii) amino optionally substituted by one to two substituents independently selected from the group consisting of alkyl, (carboxamido)alkyl, (amino)alkyl, (alkyl)carbonyl, (alkyl)sulfonyl, (alkoxy)carbonyl, (cycloalkyl)carbonyl, cycloalkyl, and heterocyclyl; iii) alkoxy optionally substituted by one to three same or different halogen; iv) carboxamido; v) hydroxyl; vi) halogen; and vii) sulfonamido; One of R¹ and R² is H, —C(O)N(R^(a))(R^(b)), or —[CH(OH)]_(n)R⁸, the other is H, —C(O)N(R^(a))(R^(b)), —N(R^(d))(R^(e)), —[CH(OH)]_(n)R⁸, —S(O)₂N(R^(a))(R^(b)), —OR⁷, or —CH₂—R⁸, provided that R¹ and R² cannot be both H; R³ is H, alkyl, haloalkyl, alkoxy, haloalkoxy, carboxamido, (hydroxy)alkyl, (dihydroxy)alkyl, or sulfonamido; R⁴ and R⁵, each independently, are H, alkyl, haloalkyl, alkoxy, haloalkoxy, amino, (alkyl)amino, (dialkyl)amino, carboxamido, hydroxyl, halogen, (hydroxyl)alkyl, (dihydroxyl)alkyl, or sulfonamido; R⁷ is optionally-substituted cycloalkyl, or optionally-substituted heterocyclyl; R⁸ is H, alkyl, optionally-substituted heterocyclyl, or —C(O)N(R¹²)(R¹³); R^(a), each independently, is H, optionally-substituted alkyl, optionally-substituted heteroaryl, or optionally-substituted heterocyclyl; R^(b), each independently, is H, optionally-substituted alkyl, optionally-substituted heteroaryl, or optionally-substituted heterocyclyl; or R^(a) and R^(b), taken together with the nitrogen atom to which they both are attached, form a 3- to 8-membered optionally-substituted heterocyclyl; R^(d) and R^(c), each independently, are selected from the group of 1) H; 2) alkyl optionally substituted by one or three substituents independently selected from the group of amino, (alkyl)amino, (alkyl)carbonyl, (alkoxy)carbonyl, carboxy, optionally-substituted aryl, optionally-substituted heteroaryl, ureido, guanidino, halogen, hydroxyl, (alkyl)sulfanyl, sulfanyl, and caboxamido; 3) heterocyclyl optionally substituted by one or two substituents independently selected from the group of halogen, alkyl, amino, (alkyl)amino, (alkyl)carbonyl, carboxy, (alkoxy)carbonyl, and caboxamido; 4) (alkyl)carbonyl optionally substituted by one or two substituents independently selected from the group of amino, hydroxyl, and alkoxy; and 5) (alkyl)sulfonyl optionally substituted by one or two substituents independently selected from the group of halogen, optionally-substituted heterocyclyl, and alkoxy; or R^(d) and R^(c), taken together with the nitrogen atom to which they both are attached, form a 5- to 6-membered optionally substituted heterocyclyl; and One of R¹² and R¹³ is H, the other is H or alkyl.
 8. The compound of any one of claims 1-7, wherein R³, R⁴, and R⁵ are all H.
 9. The compound of any one of claims 1-8, wherein at least one of R¹ and R² is H, —C(O)N(R^(a))(R^(b)), or —[CH(OH)]_(n)R⁸.
 10. The compound of any one of claims 1-9, wherein R¹ is or —C(O)N(R^(a))(R^(b)).
 11. The compound of any one of claims 1-10, wherein R¹ is —C(O)N(R^(a))(R^(b)), and wherein one of R^(a) and R^(b) is H, the other is H or (C₁₋₃)alkyl.
 12. The compound of claim 11, wherein R¹ is —C(O)NH₂.
 13. The compound of any one of claims 1-10, wherein R¹ is H.
 14. The compound of any one of claims 1-13, wherein R² is H, —N(R^(d))(R^(e)), —[CH(OH)]₂R⁸, —OR⁷, or —CH₂—R^(B), provided that R¹ and R² cannot be both H.
 15. The compound of any one of claims 1-14, wherein R² is —N(R^(d))(R^(c)), and one of R^(d) and R^(e) is H, the other is selected from the group consisting of:

Wherein y is 0, 1, 2, 3 or 4; x is 1, 2, or 3: R¹⁴ is H or optionally-substituted (C₁₋₆)alkyl, wherein said optionally-substituted (C₁₋₆) alkyl is optionally substituted by —S(C₁₋₃alkyl), hydroxyl, —SH, —C(O)NH₂, —C(O)OH, —NHC(═NH)NH₂, amino, heteroaryl, or aryl optionally substituted by hydroxyl or (C₁₋₃)alkoxy; R^(2a) and R^(2b), each independently, are H or (C₁₋₆)alkyl; or R^(2a) and R^(2b), taken together with the nitrogen atom to which they are attached, form a 3- to 8-membered heterocyclyl optionally substituted one or two substituents independently selected from the group of alkyl, haloalkyl, (alkoxy)carbonyl, amino, alkoxy, and carboxamido.
 16. The compound of any one of claims 1-14, wherein R² is —N(R^(d))(R^(e)), and one of R^(d) and R^(e) is H the other is (C₁₋₆alkyl)carbonyl optionally substituted by one or two hydroxyl groups.
 17. The compound of claim 16, wherein R¹ is —N(R^(d))(R^(e)), and one of R^(d) and R^(e) is H, the other is selected from the group consisting of:


18. The compound of any one of claims 1-14, wherein R² is —N(R^(d))(R^(e)), and R^(d) and R^(e), taken together with the nitrogen atom to which they both are attached, form an optionally substituted 5- to 6-membered heterocyclyl.
 19. The compound of claim 18, wherein R^(d) and R, taken together with the nitrogen atom to which they both are attached, form a 5- to 6-membered heterocyclyl selected from the group consisting of

wherein said 5- to 6-membered heterocyclyl is optionally substituted by one or two same or different substituents selected from the group of hydroxyl, carboxamido, (C₁₋₃)alkoxy, (C₁₋₃)alkyl, (C₁₋₃alkyl)carbonyl, and halo(C₁₋₃)alkyl.
 20. The compound of any one of claims 1-14, wherein R² is —OR⁷, and R⁷ is optionally-substituted heterocyclyl selected from the group consisting of:

wherein u is 1, 2, or
 3. 21. The compound of any one of claims 1-14, wherein R² is —[CH(OH)]₂R⁸.
 22. The compound of claim 21, wherein R⁸ is H, (C₁₋₃)alkyl, or —C(O)NH₂.
 23. The compound of claim 21 or 22, wherein R² is selected from the group the group consisting of:


24. The compound of any one of claims 1-13, wherein R² is —S(O)₂N(R^(a))(R^(b)).
 25. The compound of claim 24, wherein one of R^(a) and R^(b) is H, and the other is 5-membered heteroaryl.
 26. The compound of any one of claims 1-5 and 7-25, wherein said compound is of Formula III:

or a pharmaceutically acceptable salt, solvate, hydrate, N-oxide, or diastereomer thereof.
 27. The compound of any one of claims 1-5 and 7-25, wherein said compound is of Formula IV:

or a pharmaceutically acceptable salt, solvate, hydrate, N-oxide, or diastereomer thereof.
 28. The compound of any one of claims 1-5 and 7-25, wherein said compound is of Formula V:

or a pharmaceutically acceptable salt, solvate, hydrate, N-oxide, or diastereomer thereof.
 29. The compound of any one of claims 1-4 and 6-25, wherein said compound is of Formula VI:

or a pharmaceutically acceptable salt, solvate, hydrate, N-oxide, or diastereomer thereof.
 30. The compound of any one of claims 1-29, wherein A is optionally-substituted phenyl.
 31. The compound of any one of claims 1-25 and 30, wherein said compound is of Formula VII, or a pharmaceutically acceptable salt, solvate, hydrate, N-oxide, or diastereomer thereof:

Wherein W¹, W², and W³, each independently, are CH or N, provided that at least one of W¹, W² and W³ is N; and R^(1a) is selected from the group consisting of H, (C₁₋₃)alkyl, halo(C₁₋₃)alkyl, halo(C₁₋₃)alkoxy, (C₁₋₃)alkoxy, halogen, amino, —C(O)NH₂, [(C₁₋₃)alkyl]amino, and hydroxyl.
 32. The compound of any one of claims 1-25, wherein A is optionally-substituted 6-membered heteroaryl.
 33. The compound of claim 32, wherein A is optionally-substituted pyridyl, optionally-substituted pyrimidyl, or optionally-substituted triazinyl.
 34. The compound of any one of claims 1-25 and 32-33, wherein said compound is of Formula VIII or a pharmaceutically acceptable salt, solvate, hydrate, N-oxide, or diastereomer thereof:

Wherein W¹, W², and W³, each independently, are CH or N, provided that at least one of W¹, W² and W³ is N; and R^(1b) is selected from the group consisting of H, (C₁₋₃)alkyl, halo(C₁₋₃)alkyl, halo(C₁₋₃)alkoxy, (C₁₋₃)alkoxy, halogen, amino, —C(O)NH₂, [(C₁₋₃)alkyl]amino, and hydroxyl.
 35. The compound of any one of claims 1-25, wherein A is optionally-substituted cyclohexyl or optionally-substituted cyclohexenyl.
 36. The compound of claim 1, wherein said compound is selected from the group of: i) (S)-6-((1-amino-1-oxopropan-2-yl)amino)-2-(5-(4-(trifluoromethyl)phenyl)-3,4-dihydroisoquinolin-2(1H)-yl)pyrimidine-4-carboxamide (Compound 22); ii) (S)-6-((1-amino-1-oxopropan-2-yl)amino)-2-(5-(5-(trifluoromethyl)pyridin-2-yl)-3,4-dihydroisoquinolin-2(1H)-yl)pyrimidine-4-carboxamide (Compound 23); iii) (S)-6-((1-amino-1-oxopropan-2-yl)amino)-2-(5-(2-(trifluoromethyl)phenyl)-3,4-dihydroisoquinolin-2(1H)-yl)pyrimidine-4-carboxamide (Compound 24); iv) 6-(5-(4-(trifluoromethyl)phenyl)-3,4-dihydroisoquinolin-2(1H)-yl)picolinamide (Compound 25); v) (2S,3R)-2,3-dihydroxy-3-(6-(5-(4-(trifluoromethyl)phenyl)-3,4-dihydroisoquinolin-2(1H)-yl)pyridin-2-yl)propanamide (Compound 26); vi) (S)-6-((1-amino-1-oxopropan-2-yl)amino)-2-(5-(3-(trifluoro-methyl)phenyl)-3,4-dihydro-isoquinolin-2(1H)-yl)pyrimidine-4-carboxamide (Compound 27); vii) (S)-6-((1-amino-1-oxopropan-2-yl)amino)-2-(5-(cyclohex-1-en-1-yl)-3,4-dihydro-isoquinolin-2(1H)-yl)pyrimidine-4-carboxamide (Compound 28); viii)N-(1,2,4-thiadiazol-5-yl)-6-(5-(4-(trifluoromethyl)phenyl)-34-dihydro-isoquinolin-2(1H)-yl)pyridine-2-sulfonamide (Compound 29); ix) (S)-6-((1-amino-1-oxopropan-2-yl)amino)-2-(5-cyclohexyl-3,4-dihydro-isoquinolin-2(1H)-yl)pyrimidine-4-carboxamide (Compound 31); x) (S)-6-(1,2-dihydroxyethyl)-4-(5-(4-(trifluoromethyl)phenyl)-3,4-dihydro-isoquinolin-2(1H)-yl)picolinamide (Compound 35); and xi) (R)-6-(1,2-dihydroxyethyl)-4-(5-(4-(trifluoromethyl)phenyl)-3,4-dihydro-isoquinolin-2(1H)-yl)picolinamide (Compound 36); or a pharmaceutically acceptable salt, solvate, hydrate, N-oxide, or diastereomer thereof.
 37. A pharmaceutical composition comprising the compound of any one of claims 1-36 and a pharmaceutically acceptable carrier or diluent.
 38. A method of treating a disorder responsive to blockade of one or more sodium channels in a mammal suffering from said disorder, comprising administering to a mammal in need of such treatment an effective amount of a compound of any one of claims 1-36.
 39. The method of claim 38, wherein said disorder is responsive to blockade of TTX-resistant sodium channels.
 40. The method of claim 38, wherein said disorder is responsive to blockade of TTX-sensitive sodium channels.
 41. The method of claim 38, wherein said disorder is responsive to blockade of Na_(v)1.7 sodium channels.
 42. A method for treating a disorder or providing local anesthesia in a mammal identified as in need thereof, comprising administering to said mammal an effective amount of a compound of any one of claims 1-36, wherein said disorder is selected from the group of stroke, neuronal damage resulting from head trauma, epilepsy, seizures, neuronal loss following global and focal ischemia, pain, migraine, primary erythromelalgia, paroxysmal extreme pain disorder, cerebellar atrophy, ataxia, mental retardation, a neurodegenerative disorder, manic depression, tinnitus, myotonia, a movement disorder, and cardiac arrhythmia.
 43. The method of claim 42, wherein said method is for treating pain.
 44. The method of claim 42, wherein said method is for preemptively or palliatively treating pain.
 45. The method of claim 43 or 44, wherein said pain is selected from the group consisting of chronic pain, inflammatory pain, neuropathic pain, acute pain, and surgical pain.
 46. A method of modulating sodium channels in a mammal, comprising administering to the mammal at least one compound of any one of claims 1-36.
 47. The method of claim 46, wherein the Na_(v)1.7 sodium channel is modulated.
 48. A pharmaceutical composition comprising the compound of any one of claims 1-36, for treating a disorder responsive to blockade of sodium ion channels.
 49. A compound of any one of claims 1-36 for use in treating a disorder responsive to blockade of sodium ion channels.
 50. A radiolabeled compound that is ³H, ¹¹C, or ¹⁴C radiolabeled of a compound claimed in any one of claims 1-36.
 51. A method of screening a candidate compound for the ability to bind to a binding site on a protein using the radiolabeled compound of claim 50, comprising a) introducing a fixed concentration of the radiolabeled compound to a soluble or membrane-associated protein or fragment thereof to form a mixture; b) titrating the mixture with a candidate compound; and c) determining the binding of the candidate compound to said binding site.
 52. A method of preparing a pharmaceutical composition, comprising admixing a therapeutically effective amount of a compound of any one of claims 1-36, with a pharmaceutically acceptable diluent or carrier.
 53. A compound of any one of claims 1-36 for use in the treatment of stroke, neuronal damage resulting from head trauma, epilepsy, seizures, neuronal loss following global and focal ischemia, pain, migraine, primary erythromelalgia, paroxysmal extreme pain disorder, cerebellar atrophy, ataxia, mental retardation, a neurodegenerative disorder, manic depression, tinnitus, myotonia, a movement disorder, or cardiac arrhythmia, or providing local anesthesia.
 54. The compound of claim 53 for use in the treatment of pain.
 55. The compound of claim 53 or 54 for use in preemptive or palliative treatment of pain.
 56. The compound of claim 54 or 55, wherein said pain is selected from the group consisting of chronic pain, inflammatory pain, neuropathic pain, acute pain, and surgical pain.
 57. Use of a compound of any one of claims 1-36 in the preparation of a medicament for the treatment of stroke, neuronal damage resulting from head trauma, epilepsy, seizures, neuronal loss following global and focal ischemia, pain, migraine, primary erythromelalgia, paroxysmal extreme pain disorder, cerebellar atrophy, ataxia, mental retardation, a neurodegenetive disorder, manic depression, tinnitus, myotonia, a movement disorder, or cardiac arrhythmia, or providing local anesthesia.
 58. Use as claimed in claim 57 in the treatment of pain.
 59. Use as claimed in claim 57 or 58 in preemptive or palliative treatment of pain.
 60. Use as claimed in claim 58 or 59, wherein said pain is selected from the group consisting of chronic pain, inflammatory pain, neuropathic pain, acute pain, and surgical pain. 